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1.
Cell ; 183(3): 620-635.e22, 2020 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-33035454

RESUMO

Hippocampal activity represents many behaviorally important variables, including context, an animal's location within a given environmental context, time, and reward. Using longitudinal calcium imaging in mice, multiple large virtual environments, and differing reward contingencies, we derived a unified probabilistic model of CA1 representations centered on a single feature-the field propensity. Each cell's propensity governs how many place fields it has per unit space, predicts its reward-related activity, and is preserved across distinct environments and over months. Propensity is broadly distributed-with many low, and some very high, propensity cells-and thus strongly shapes hippocampal representations. This results in a range of spatial codes, from sparse to dense. Propensity varied ∼10-fold between adjacent cells in salt-and-pepper fashion, indicating substantial functional differences within a presumed cell type. Intracellular recordings linked propensity to cell excitability. The stability of each cell's propensity across conditions suggests this fundamental property has anatomical, transcriptional, and/or developmental origins.


Assuntos
Hipocampo/anatomia & histologia , Hipocampo/fisiologia , Animais , Comportamento Animal/fisiologia , Fenômenos Biofísicos , Cálcio/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Modelos Neurológicos , Células Piramidais/fisiologia , Recompensa , Análise e Desempenho de Tarefas , Fatores de Tempo
2.
Proc Natl Acad Sci U S A ; 120(12): e2220649120, 2023 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-36920925

RESUMO

Subthreshold depolarization enhances neurotransmitter release evoked by action potentials and plays a key role in modulating synaptic transmission by combining analog and digital signals. This process is known to be Ca2+ dependent. However, the underlying mechanism of how small changes in basal Ca2+ caused by subthreshold depolarization can regulate transmitter release triggered by a large increase in local Ca2+ is not well understood. This study aimed to investigate the source and signaling mechanisms of Ca2+ that couple subthreshold depolarization with the enhancement of glutamate release in hippocampal cultures and CA3 pyramidal neurons. Subthreshold depolarization increased presynaptic Ca2+ levels, the frequency of spontaneous release, and the amplitude of evoked release, all of which were abolished by blocking L-type Ca2+ channels. A high concentration of intracellular Ca2+ buffer or blockade of calmodulin abolished depolarization-induced increases in transmitter release. Estimation of the readily releasable pool size using hypertonic sucrose showed depolarization-induced increases in readily releasable pool size, and this increase was abolished by the blockade of calmodulin. Our results provide mechanistic insights into the modulation of transmitter release by subthreshold potential change and highlight the role of L-type Ca2+ channels in coupling subthreshold depolarization to the activation of Ca2+-dependent signaling molecules that regulate transmitter release.


Assuntos
Canais de Cálcio Tipo L , Cálcio , Potenciais Evocados , Ácido Glutâmico , Potenciais da Membrana , Canais de Cálcio Tipo L/metabolismo , Ácido Glutâmico/metabolismo , Calmodulina/metabolismo , Cálcio/metabolismo , Terminações Pré-Sinápticas/metabolismo , Neurotransmissores/metabolismo , Animais , Ratos , Células Cultivadas , Hipocampo/citologia , Neurônios/metabolismo , Ratos Sprague-Dawley , Transmissão Sináptica
3.
Nano Lett ; 24(30): 9322-9330, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-38924488

RESUMO

Electrochemical CO2 reduction reaction (eCO2RR) over Cu-based catalysts is a promising approach for efficiently converting CO2 into value-added chemicals and alternative fuels. However, achieving controllable product selectivity from eCO2RR remains challenging because of the difficulty in controlling the oxidation states of Cu against robust structural reconstructions during the eCO2RR. Herein, we report a novel strategy for tuning the oxidation states of Cu species and achieving eCO2RR product selectivity by adjusting the Cu content in CuMgAl-layered double hydroxide (LDH)-based catalysts. In this strategy, the highly stable Cu2+ species in low-Cu-containing LDHs facilitated the strong adsorption of *CO intermediates and further hydrogenation into CH4. Conversely, the mixed Cu0/Cu+ species in high-Cu-containing LDHs derived from the electroreduction during the eCO2RR accelerated C-C coupling reactions. This strategy to regulate Cu oxidation states using LDH nanostructures with low and high Cu molar ratios produced an excellent eCO2RR performance for CH4 and C2+ products, respectively.

4.
Sensors (Basel) ; 24(20)2024 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-39460003

RESUMO

This study presents a novel approach to enhancing the timing performance of dual-ended positron emission tomography (PET) detectors for brain imaging by employing a dual-finishing crystal method. The proposed method integrates both polished and unpolished surfaces within the scintillation crystal block to optimize time-of-flight (TOF) and depth-of-interaction (DOI) resolutions. A dual-finishing detector was constructed using an 8 × 8 LGSO array with a 2 mm pitch, and its performance was compared against fully polished and unpolished crystal blocks. The results indicate that the dual-finishing method significantly improves the timing resolution while maintaining good energy and DOI resolutions. Specifically, the timing resolution achieved with the dual-finishing block was superior, measuring 192.0 ± 12.8 ps, compared to 206.3 ± 9.4 ps and 234.8 ± 17.9 ps for polished and unpolished blocks, respectively. This improvement in timing is crucial for high-performance PET systems, particularly in brain imaging applications where high sensitivity and spatial resolution are paramount.


Assuntos
Encéfalo , Tomografia por Emissão de Pósitrons , Tomografia por Emissão de Pósitrons/métodos , Encéfalo/diagnóstico por imagem , Humanos , Desenho de Equipamento
5.
Nano Lett ; 23(11): 5092-5100, 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37212638

RESUMO

Highly efficient electrocatalysts for the oxygen evolution reaction (OER) in neutral electrolytes are indispensable for practical electrochemical and photoelectrochemical water splitting technologies. However, there is a lack of good, neutral OER electrocatalysts because of the poor stability when H+ accumulates during the OER and slow OER kinetics at neutral pH. Herein, we report Ir species nanocluster-anchored, Co/Fe-layered double hydroxide (LDH) nanostructures in which the crystalline nature of LDH-restrained corrosion associated with H+ and the Ir species dramatically enhanced the OEC kinetics at neutral pH. The optimized OER electrocatalyst demonstrated a low overpotential of 323 mV (at 10 mA cm-2) and a record low Tafel slope of 42.8 mV dec-1. When it was integrated with an organic semiconductor-based photoanode, we obtained a photocurrent density of 15.2 mA cm-2 at 1.23 V versus reversible hydrogen in neutral electrolyte, which is the highest among all reported photoanodes to our knowledge.

6.
Small ; 19(20): e2300240, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36794290

RESUMO

Electrocatalysts facilitating chlorine evolution reaction (ClER) play a vital role in chlor-alkali industries. Owing to a huge amount of chlorine consumed worldwide, inexpensive high-performing catalysts for Cl2 production are highly demanded. Here, a superb ClER catalyst fabricated through uniform dispersion of Pt single atoms (SAs) in C2 N2 moieties of N-doped graphene (denoted as Pt-1) is presented, which demonstrates near 100% exclusive ClER selectivity, long-term durability, extraordinary Cl2 production rate (3500 mmol h-1 gPt -1 ), and >140 000-fold increased mass activity over industrial electrodes in acidic medium. Excitingly, at the typical chlor-alkali industries' operating temperature (80 °C), Pt-1 supported on carbon paper electrode requires a near thermoneutral ultralow overpotential of 5 mV at 1 mA cm-2 current density to initiate the ClER, consistent with the predicted density functional theory (DFT) calculations. Altogether these results show the promising electrocatalyst of Pt-1 toward ClER.

7.
Clin Orthop Relat Res ; 481(10): 1966-1974, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37053082

RESUMO

BACKGROUND: Although brachial plexus block in volar plating surgery for distal radius fractures is reportedly associated with lower postoperative pain scores, rebound pain has been reported to occur after the initial block wears off. Dexamethasone can be used in multimodal strategies for antiemesis and to control pain postoperatively. Although prior studies have suggested that anesthesia can be prolonged by adding dexamethasone to regional blocks, no randomized trials we are aware of have ascertained whether doing so will make a clinically important difference in pain after surgery for distal radius fractures. QUESTIONS/PURPOSES: Do patients who receive supplemental dexamethasone in a brachial plexus block for volar plating of unstable distal radius fractures have (1) better pain scores at 4, 8, 24, and 48 hours postoperatively than patients who have not received dexamethasone, and (2) lower fentanyl consumption and administration of antiemetic drugs without change in serum blood glucose, as well as a longer analgesic duration from the block after surgery than patients who have not received dexamethasone? METHODS: This randomized, double-blind trial included 69 patients undergoing surgery for distal radius fractures under ultrasound-guided supraclavicular brachial plexus blocks who were randomly allocated into two groups: a nondexamethasone group receiving a brachial plexus block with 0.5% ropivacaine and a dexamethasone group receiving 0.5% ropivacaine and 5 mg of dexamethasone. Thirty-four patients were allocated to the dexamethasone group and 35 were allocated to the nondexamethasone group. Nine patients (four in the dexamethasone group and five in the nondexamethasone group) were excluded after randomization because local anesthetics were used during their surgical procedures owing to an incomplete block or they requested patient-controlled analgesia after surgery. The treatment groups did not differ in any important ways, including age, gender, BMI, hand dominance, and AO/Orthopaedic Trauma Association classification. All patients received the same surgical procedure and perioperative care protocol, except for the injected agents during their brachial plexus block. The primary outcome was postoperative pain, evaluated using a 10-mm VAS at 4, 8, 12, 24, and 48 hours after surgery. The minimum clinically important difference for the VAS score was 2 of 10 points. Secondary outcome variables included fentanyl administration as a rescue analgesic, the number of patients receiving antiemetic medications because of fentanyl administration, and the duration of brachial plexus block. Serum blood glucose was measured 1 day before, immediately after, and 24 hours after surgery. Patients, surgeons, and outcome assessors were blinded to treatment allocation. RESULTS: The only clinically important between-group difference in VAS pain scores was at 8 hours, favoring the group that received dexamethasone over the group that did not (1.9 ± 1.6 versus 4.7 ± 2.7; mean difference -2.8 [95% CI -3.9 to -1.6]; p < 0.001). After brachial plexus block, the most severe pain score in both groups was reported at 12 hours postoperatively and gradually diminished over time. There was no between-group difference in fentanyl use between those who received dexamethasone and those who did not (21 ± 38 mcg versus 31 ± 29 mcg; mean difference -10 [95% CI -27.4 to 7.4]; p = 0.26). Furthermore, the use of antiemetics did not differ between the groups (27% [eight of 30] versus 37% [11 of 30]; odds ratio 1.6 [95% CI 0.5 to 4.8]; p = 0.41). Baseline and 24-hour postoperative serum blood glucose level did not differ between the groups. However, the immediately postoperative serum blood glucose level was higher in the dexamethasone group than in the nondexamethasone group (121 ± 29 versus 104 ± 20; mean difference 16 [95% CI 3.3 to 28.8]; p = 0.02). The brachial plexus block duration was 3 hours longer (95% CI 0.8 to 5.2 hours) in the dexamethasone group than that in the nondexamethasone group (11 ± 5 hours versus 8 ± 3 hours; p = 0.01). CONCLUSION: The postoperative pain level in patients who received supplemental dexamethasone in a regional block was not clinically different from that of patients who received conventional brachial plexus block anesthesia when undergoing volar plating for distal radius fractures. However, patients who received a brachial plexus block with dexamethasone experienced slight prolongation of their block and decrease in pain 8 hours after surgery. LEVEL OF EVIDENCE: Level I, therapeutic study.


Assuntos
Bloqueio do Plexo Braquial , Fraturas do Punho , Humanos , Ropivacaina , Método Duplo-Cego , Glicemia , Anestésicos Locais , Dor Pós-Operatória/diagnóstico , Dor Pós-Operatória/etiologia , Dor Pós-Operatória/prevenção & controle , Analgésicos , Dexametasona , Fentanila/uso terapêutico
8.
Phys Rev Lett ; 129(12): 120603, 2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36179191

RESUMO

Landauer's bound is the minimum thermodynamic cost for erasing one bit of information. As this bound is achievable only for quasistatic processes, finite-time operation incurs additional energetic costs. We find a tight finite-time Landauer's bound by establishing a general form of the classical speed limit. This tight bound well captures the divergent behavior associated with the additional cost of a highly irreversible process, which scales differently from a nearly irreversible process. We also find an optimal dynamics which saturates the equality of the bound. We demonstrate the validity of this bound via discrete one-bit and coarse-grained bit systems. Our Letter implies that more heat dissipation than expected occurs during high-speed irreversible computation.

9.
Eur J Nucl Med Mol Imaging ; 49(6): 1833-1842, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34882262

RESUMO

PURPOSE: This study aims to compare two approaches using only emission PET data and a convolution neural network (CNN) to correct the attenuation (µ) of the annihilation photons in PET. METHODS: One of the approaches uses a CNN to generate µ-maps from the non-attenuation-corrected (NAC) PET images (µ-CNNNAC). In the other method, CNN is used to improve the accuracy of µ-maps generated using maximum likelihood estimation of activity and attenuation (MLAA) reconstruction (µ-CNNMLAA). We investigated the improvement in the CNN performance by combining the two methods (µ-CNNMLAA+NAC) and the suitability of µ-CNNNAC for providing the scatter distribution required for MLAA reconstruction. Image data from 18F-FDG (n = 100) or 68 Ga-DOTATOC (n = 50) PET/CT scans were used for neural network training and testing. RESULTS: The error of the attenuation correction factors estimated using µ-CT and µ-CNNNAC was over 7%, but that of scatter estimates was only 2.5%, indicating the validity of the scatter estimation from µ-CNNNAC. However, CNNNAC provided less accurate bone structures in the µ-maps, while the best results in recovering the fine bone structures were obtained by applying CNNMLAA+NAC. Additionally, the µ-values in the lungs were overestimated by CNNNAC. Activity images (λ) corrected for attenuation using µ-CNNMLAA and µ-CNNMLAA+NAC were superior to those corrected using µ-CNNNAC, in terms of their similarity to λ-CT. However, the improvement in the similarity with λ-CT by combining the CNNNAC and CNNMLAA approaches was insignificant (percent error for lung cancer lesions, λ-CNNNAC = 5.45% ± 7.88%; λ-CNNMLAA = 1.21% ± 5.74%; λ-CNNMLAA+NAC = 1.91% ± 4.78%; percent error for bone cancer lesions, λ-CNNNAC = 1.37% ± 5.16%; λ-CNNMLAA = 0.23% ± 3.81%; λ-CNNMLAA+NAC = 0.05% ± 3.49%). CONCLUSION: The use of CNNNAC was feasible for scatter estimation to address the chicken-egg dilemma in MLAA reconstruction, but CNNMLAA outperformed CNNNAC.


Assuntos
Aprendizado Profundo , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Fluordesoxiglucose F18 , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Tomografia por Emissão de Pósitrons/métodos
10.
Eur J Nucl Med Mol Imaging ; 49(9): 3061-3072, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35226120

RESUMO

PURPOSE: Alzheimer's disease (AD) studies revealed that abnormal deposition of tau spreads in a specific spatial pattern, namely Braak stage. However, Braak staging is based on post mortem brains, each of which represents the cross section of the tau trajectory in disease progression, and numerous studies were reported that do not conform to that model. This study thus aimed to identify the tau trajectory and quantify the tau progression in a data-driven approach with the continuous latent space learned by variational autoencoder (VAE). METHODS: A total of 1080 [18F]Flortaucipir brain positron emission tomography (PET) images were collected from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. VAE was built to compress the hidden features from tau images in latent space. Hierarchical agglomerative clustering and minimum spanning tree (MST) were applied to organize the features and calibrate them to the tau progression, thus deriving pseudo-time. The image-level tau trajectory was inferred by continuously sampling across the calibrated latent features. We assessed the pseudo-time with regard to tau standardized uptake value ratio (SUVr) in AD-vulnerable regions, amyloid deposit, glucose metabolism, cognitive scores, and clinical diagnosis. RESULTS: We identified four clusters that plausibly capture certain stages of AD and organized the clusters in the latent space. The inferred tau trajectory agreed with the Braak staging. According to the derived pseudo-time, tau first deposits in the parahippocampal and amygdala, and then spreads to the fusiform, inferior temporal lobe, and posterior cingulate. Prior to the regional tau deposition, amyloid accumulates first. CONCLUSION: The spatiotemporal trajectory of tau progression inferred in this study was consistent with Braak staging. The profile of other biomarkers in disease progression agreed well with previous findings. We addressed that this approach additionally has the potential to quantify tau progression as a continuous variable by taking a whole-brain tau image into account.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Doença de Alzheimer/metabolismo , Encéfalo/metabolismo , Carbolinas , Disfunção Cognitiva/metabolismo , Progressão da Doença , Humanos , Tomografia por Emissão de Pósitrons/métodos , Proteínas tau/metabolismo
11.
Mol Psychiatry ; 26(7): 3476-3488, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-32929214

RESUMO

Although antipsychotic drugs are effective for relieving the psychotic symptoms of first-episode psychosis (FEP), psychotic relapse is common during the course of the illness. While some FEPs remain remitted even without medication, antipsychotic discontinuation is regarded as the most common risk factor for the relapse. Considering the actions of antipsychotic drugs on presynaptic and postsynaptic dopamine dysregulation, this study evaluated possible mechanisms underlying relapse after antipsychotic discontinuation. Twenty five FEPs who were clinically stable and 14 matched healthy controls were enrolled. Striatal dopamine activity was assessed as Kicer value using [18F]DOPA PET before and 6 weeks after antipsychotic discontinuation. The D2/3 receptor availability was measured as BPND using [11C]raclopride PET after antipsychotic discontinuation. Healthy controls also underwent PET scans according to the corresponding schedule of the patients. Patients were monitored for psychotic relapse during 12 weeks after antipsychotic discontinuation. 40% of the patients showed psychotic relapse after antipsychotic discontinuation. The change in Kicer value over time significantly differed between relapsed, non-relapsed patients and healthy controls (Week*Group: F = 4.827, df = 2,253.193, p = 0.009). In relapsed patients, a significant correlation was found between baseline striatal Kicer values and time to relapse after antipsychotic discontinuation (R2 = 0.518, p = 0.018). BPND were not significantly different between relapsed, non-relapsed patients and healthy controls (F = 1.402, df = 2,32.000, p = 0.261). These results suggest that dysfunctional dopamine autoregulation might precipitate psychotic relapse after antipsychotic discontinuation in FEP. This finding could be used for developing a strategy for the prevention of psychotic relapse related to antipsychotic discontinuation.


Assuntos
Antipsicóticos , Transtornos Psicóticos , Antipsicóticos/uso terapêutico , Di-Hidroxifenilalanina , Dopamina/uso terapêutico , Humanos , Tomografia por Emissão de Pósitrons , Transtornos Psicóticos/diagnóstico por imagem , Transtornos Psicóticos/tratamento farmacológico , Racloprida , Recidiva
12.
Clin Orthop Relat Res ; 480(4): 762-770, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-34694249

RESUMO

BACKGROUND: Ultrasonography (US)-guided steroid injections can improve the accuracy of injection in patients with de Quervain disease, especially in those with an intracompartmental septum. Although the main lesion of de Quervain disease in patients with a septum is a stenosing tenosynovitis of the extensor pollicis brevis (EPB), no report we know of has compared injection into the EPB subcompartment with an injection into both the abductor pollicis longus (APL) and EPB subcompartments. In this randomized trial, we compared the results of US-guided steroid injections targeting both subcompartments and the EPB subcompartment alone in patients with de Quervain disease. QUESTIONS/PURPOSES: (1) Do patients who receive a steroid injection in the EPB subcompartment alone have lower pain scores at 6 weeks and at 3 months after US-guided injection compared with patients who receive an injection in both subcompartments? (2) Do patients who receive a steroid injection in the EPB subcompartment alone experience fewer steroid injection-related complications than patients who receive an injection in both subcompartments? METHODS: A randomized controlled study was performed at a single center between August 2018 and March 2021. Patients with a diagnosis of de Quervain disease and with a complete intracompartmental septum between the APL and the EPB tendons were included. In total, 112 patients had a diagnosis of de Quervain disease during the study period. Definite, complete subcompartmentalization was seen in 50 patients. Patients were randomly assigned to US-guided injections targeting both subcompartments (n = 25) or the EPB subcompartment alone (n = 25). There were no between-group differences in age, gender, affected wrist, or disease duration, and all patients had US evidence of tendinosis of the EPB, with or without tendinosis of the APL. Although 33% of patients (16 of 48) showed tendinosis of the APL, no patient showed tendinosis of the APL alone. In all patients, a dorsal-to-palmar side injection of 0.5 mL of 2% lidocaine and 0.5 mL of triamcinolone acetonide (40 mg/mL) was administered by two experienced hand surgeons. In the both-subcompartments group, US-guided injections were performed in each of the APL and EPB subcompartments. In the EPB subcompartment group, US-guided injections were administered in the EPB subcompartment only. All patients underwent the same protocol after the procedure. Four percent (n = 2, 1 in each group) of patients were excluded after randomization because their pain level was not registered. Pre- and postinjection clinical outcome assessments were completed by orthopaedic surgery residents not involved in patient management. Patients were regularly examined at baseline, 6 weeks, and 3 months to evaluate the intensity of pain. We assessed pain by the VAS score, where 0 indicated no pain and 100 the most pain. At baseline, the VAS score was 67 ± 14 in the both-subcompartment group and 67 ± 16 in the EPB subcompartment group (mean difference 0.17 [95% CI -8.45 to 8.82]; p = 0.97). Complications related to the steroid injection, including numbness, tendon rupture, and skin hypopigmentation, were also recorded at final follow-up examinations. To determine statistical power, the VAS score for pain at 6 weeks after the injection was used as the primary outcome variable. The minimum clinically important difference for the VAS score was deemed to be 20 mm, and we estimated an SD of 23. A sample size calculation indicated that a sample of 21 patients per group would provide 80% power to detect an effect of this size between the groups at the p = 0.05 level using a t-test. RESULTS: There were no differences in the VAS scores between the both-subcompartment group and the EPB group at 6 weeks (10 ± 6 versus 10 ± 7, mean difference -0.08 [95% CI -4.08 to 3.91]; p = 0.97). The same was true at 12 weeks (12 ± 13 versus 11 ± 15, mean difference 0.38 [95% CI -7.74 to 8.49]; p = 0.09). No adverse events related to treatment (such as tendon rupture, infections, and numbness) occurred in either group. However, skin hypopigmentation occurred at the final follow-up examination in both groups. The proportion of patients experiencing skin hypopigmentation in the EPB subcompartment group was lower than in the both-subcompartment group (33% [8 of 24] versus 67% [16 of 24]; odds ratio 0.25 [95% CI 0.08 to 0.83]; p = 0.02). CONCLUSION: Our data suggest that a US-guided steroid injection targeting the EPB subcompartment alone is as effective in terms of pain reduction as targeting both subcompartments in patients with de Quervain disease who have complete septation. Furthermore, an injection targeting the EPB subcompartment alone can reduce the dose of steroids used, perhaps thereby decreasing complications related to steroid injections. We recommend using only single-compartment injections in this context, even among patients with an intracompartmental septum. LEVEL OF EVIDENCE: Level I, therapeutic study.


Assuntos
Doença de De Quervain , Hipopigmentação , Tendinopatia , Traumatismos dos Tendões , Doença de De Quervain/diagnóstico por imagem , Doença de De Quervain/tratamento farmacológico , Humanos , Hipestesia , Dor
13.
Plant Dis ; 2022 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-35188418

RESUMO

Clematis patens (Ranunculaceae), often called big-flower clematis, is a perennial plant native to Northeast Asia, including China, Japan, and Korea. This plant is one of the popular ornamental plants because of its large and colorful flower. In Korea, it is widely cultivated for public and private gardening and medicinal purposes. In September of 2021, symptoms of rust disease were found on C. patens at a public park (ca. 30 ha) in Jeonju (35°52'16"N, 127°03'16"E), Korea, where the disease occurred on 80% of C. patens plants (n = 50) surveyed, and disease severity in each affected plant ranged 60 to 90%. Symptoms appeared as light green, vein-limited chlorotic spots on the upper surface of infected leaves, and yellow or orange rust pustules were formed on the corresponding lower surface of leaves. A representative sample was deposited in the Kunsan National University Herbarium (KSNUH1522). Uredinia were yellow or orange, round to ellipsoidal, mostly scattered, and 0.5-1 mm in diameter. Urediniospores were pale yellow, ellipsoid or ovoid, 23.1 to 34.8 × 14.9 to 24.7 (average 29.3 ± 2.7 × 18.8 ± 2.2 µm [mean ± SD], n = 50) µm with a verrucose and hyaline wall of 1.0-2.0 µm thick. The morphological characteristics were similar to those reported for Coleosporium clematidis (Barclay 1889, Hiratsuka et al. 1992). To confirm morphological identification, genomic DNA was extracted from a representative specimen (KSNUH1522). The internal transcribed spacer (ITS) rDNA with primers ITS5-u and ITS4rust (Pfunder and Schürch 2001) and large subunit (LSU) rDNA with primers LRust1R and LRust3 (Beenken et al. 2012) were amplified for sequencing. Two resulting sequences (Acc. Nos. OM200310 for ITS, OM184262 for LSU) were blasted in GenBank. The ITS sequence of the Korean sample differs at a nucleotide with a sequence of C. clematidis from Clematis sp. (KX386005) but at eight nucleotides with other three sequences of C. clematidis (KX386007, KX386008 and KX386010). The LSU sequence differs at a nucleotide from the sequences of C. clematidis from Clematis sp. (KX386039, KX386040, KX386042). In phylogenetic trees of the ITS and LSU sequences, the Korean isolate formed a well-supported clade with the reference sequences of C. clematidis. For a pathogenicity test, urediniospores (1.25 ×106/ml) were harvested from the infected leaves and inoculated onto three healthy C. patens. Three non-inoculated plants served as controls. Inoculated and non-inoculated plants were kept in a plant growth chamber at 22°C, a 16/8 h of light cycle, 80% humidity. After three weeks, all inoculated plants formed yellow rust pustules on the lower surface of leaves, identical to what was previously observed in the field, whereas the control plants remained symptomless. The same pathogen was confirmed from the symptomatic plants, fulfilling Koch's postulates. Based on morphological characteristics, sequence data and pathogenicity test, the causal agent of rust on Clematis patens was identified as C. clematidis. To our knowledge, this is the first report of rust disease caused by C. clematidis on C. patens in Korea and previously recorded only in Japan (Hiratsuka et al. 1992). Coleosporium clematidis has been reported on about 60 species of Clematis in Asia and Africa but has not been reported in Europe and North America (Farr and Rossman 2022). In Korea, Clematis fusca var. violacea was previously reported as a host plant for the causal pathogen (Cho and Shin 2004). Given the high occurrence and severe damage, this disease could be a potential threat to the cultivation of C. patens.

14.
Plant Dis ; 2022 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-35787005

RESUMO

Malva verticillata (Malvaceae), commonly called Chinese mallow or whorled mallow, is an annual herb native to East Asia and is currently distributed worldwide. In Korea, this plant is cultivated as a leafy vegetable and cooked like spinach or used in soups and also as a medicine material. In March 2022, typical symptoms of rust disease were observed on M. verticillata in a plastic house (37°22'12″ N, 127°34'30" E) in Yeoju, Korea. Yellow or light green round chlorotic spots appeared on the upper surface of infected leaves, while reddish-brown or dark brown rust pustules formed on its lower surface. Infection occurred in 10% of M. verticillata plants surveyed, and disease severity ranged between 30-90%. A representative sample was deposited in the Kunsan National University Herbarium (KSNUH1762). Telia were mostly hypophyllous, reddish-brown to dark brown, round, mostly grouped, and 0.3-0.7 mm in diameter. Teliospores were mostly two-celled, but rarely one or three-celled, yellowish to light brown, fusoid, and 42.9-101 × 10.8- to 18.8 µm (average 72.7 ± 12.3 × 14.2 ± 1.92 µm [mean ± SD]; n = 50), with a smooth, hyaline to yellowish wall of 1.0-2.5 µm thickness. The morphological characteristics were similar to those reported for Puccinia modiolae (Aime and Abbasi 2018; Albu et al. 2019). To confirm the morphological identification, genomic DNA was extracted from the teliospores of an infected leaf. The internal transcribed spacer (ITS) with primers ITS5-u and ITS4rust (Pfunder and Schürch 2001) and the large subunit (LSU) rDNA with primers LRust1R and LRust3 (Beenken et al. 2012) were amplified for sequencing. The resulting sequences were deposited in GenBank with accession numbers ON631218 for ITS and ON631226 for LSU. BLASTn search showed that the Korean sample was identical to the ITS sequences of P. modiolae from Modiola caroliniana (MK458693-MK458697) and the LSU sequences from M. caroliniana, Malva sylvestris, and Alcea rosea (MH742976, MH742977, and MH742978). In the phylogenetic trees of the ITS and LSU sequences, the Korean sample was grouped with the reference sequences of P. modiolae, with the maximum supporting value. For the pathogenicity test, rust-infected leaf discs were placed on the upper or lower surfaces of leaves of three healthy M. verticillata. Three non-inoculated plants served as controls. Inoculated and non-inoculated plants were maintained in a growth chamber at 22°C, a 16/8 h light cycle, and 80% humidity. After three weeks, all inoculated plants developed evident rust symptoms on the upper and lower surfaces of the leaves on which the leaf discs were placed, whereas the control plants remained symptomless. The pathogen present on the inoculated plants was confirmed to be the same pathogen as that observed in the field, fulfilling Koch's postulates. Based on the morphological investigation, sequence analysis, and pathogenicity tests, P. modiolae was identified as the causal agent of rust disease on M. verticillata. To date, this pathogen has been reported on seven Malvaceae plants, including Alcea rosea, Althaea officinalis, Lavatera arborea, Malva parviflora, Malva sylvestris, Modiola caroliniana, and Modiola sp., in North and South America (Farr and Rossman 2022). However, it has not been reported in Asia or Korea. This study is the first report of rust disease on M. verticillata worldwide. Considering its high incidence rate and severe damage, this pathogen is a potential concern for the cultivation of M. verticillata in Korea. This finding could contribute to developing phytosanitary and control treatments for this disease.

15.
J Shoulder Elbow Surg ; 31(2): 428-436, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34656779

RESUMO

BACKGROUND: Although surgical treatment is considered reliable for lateral elbow tendinosis, local injection therapy may be preferable, as it avoids surgery. Among a number of local injections, platelet-rich plasma has been used successfully to treat lateral elbow tendinosis. The purpose of this study was to compare the outcomes in patients treated with either platelet-rich plasma injections or surgery for lateral elbow tendinosis using a systematic literature review and meta-analysis. METHODS: MEDLINE, Embase, and Cochrane Library databases were systematically searched for studies published before March 1, 2021, that compared platelet-rich plasma with operative treatment for lateral elbow tendinosis. The pooled analysis was designed to compare the visual analog scale scores and the Patient-Related Tennis Elbow Evaluation scores between the platelet-rich plasma and surgical treatment groups at serial time points. RESULTS: We included 5 studies involving 340 patients with lateral elbow tendinosis, comprising of 154 patients treated with platelet-rich plasma and 186 patients who underwent surgical treatment. The pooled analysis showed no statistically significant differences in the visual analog scale scores at any of the follow-up time points, namely, 2 months (mean difference [MD] 1.11, 95% confidence interval [CI] -2.51 to 4.74, P = .55, I2 = 94%), 6 months (MD 0.80, 95% CI -2.83 to 4.42, P = .67, I2 = 92%), and 12 months (MD -0.92, 95% CI -4.63 to 2.80, P = .63, I2 = 93%) postintervention and in the Patient-Related Tennis Elbow Evaluation scores at 12 weeks (MD -1.86, 95% CI -22.30 to 18.58, P = .86, I2 = 81%), 24 weeks (MD -3.33, 95% CI -21.82 to 15.17, P = .72, I2 = 74%), and 52 weeks (MD -3.64, 95% CI -19.65 to 12.37, P = .66, I2 = 69%) postintervention. CONCLUSIONS: Local platelet-rich plasma injections and surgical treatment produced equivalent pain scores and functional outcomes in patients with lateral elbow tendinosis. Thus, platelet-rich plasma injections may represent a reasonable alternative treatment for patients who are apprehensive to proceed with surgery or for poor surgical candidates.


Assuntos
Plasma Rico em Plaquetas , Tendinopatia , Cotovelo de Tenista , Cotovelo , Humanos , Injeções , Tendinopatia/cirurgia , Cotovelo de Tenista/cirurgia , Resultado do Tratamento
16.
J Shoulder Elbow Surg ; 31(3): 634-645, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34861405

RESUMO

HYPOTHESIS: The concentration of leukocytes influences the quality of platelet-rich plasma (PRP). However, there is no consensus on which type of PRP based on the concentration of leukocytes is the best for lateral epicondylitis (LE). METHODS: We systematically searched the MEDLINE, Embase, and Cochrane Library databases until March 1, 2020. Studies involving randomized controlled trials, patients with LE, and treatment with PRP injections were included. PRP was classified into leukocyte-poor (LP) PRP and leukocyte-rich (LR) PRP. LR-PRP was defined as PRP with a white blood cell concentration exceeding that of whole blood (4.0-10.0 per µL3), whereas LP-PRP was defined as PRP with a lower white blood cell concentration than that of whole blood. The efficacy of PRP was assessed using the visual analog scale (VAS) and success rates. RESULTS: Eleven randomized controlled trials (six involving LP-PRP and five involving LR-PRP) were eligible for inclusion in this review. Eight studies were included in the meta-analysis to evaluate the VAS score. Regarding short-term follow-up, there was no difference in the VAS scores between the LP-PRP and control groups (standard mean difference [SMD], 0.01; 95% confidence interval [CI], -0.29 to 0.30; P = 0.97), with no heterogeneity (I2 = 0%). There was also no difference in the VAS scores between the LR-PRP and control groups (SMD, -0.19; 95% CI, -0.57 to 0.20; P = 0.34), with substantial heterogeneity (I2 = 56.7%). Regarding long-term follow-up, there was no difference in the VAS scores between the LP-PRP and control groups (SMD, -0.73; 95% CI, -1.69 to 0.23; P = 0.134) with substantial heterogeneity (I2 = 88.4%). The LR-PRP group had lower VAS scores than the control group (SMD, -1.06; 95% CI, -2.02 to -0.09; P = 0.032) with substantial heterogeneity (I2 = 92%). In the LP-PRP group, there was no significant difference in the success rate (odds ratio, 1.08; 95% CI, 0.07-16.47; P = 0.956) with substantial heterogeneity (I2 = 87.7%). In the LR-PRP group, however, the patients who received PRP had a higher success rate than those in the control group (odds ratio, 2.85; 95% CI, 1.67-4.85; P < 0.01) with substantial heterogeneity (I2 = 82.9%). CONCLUSION: LR-PRP may provide pain relief and successful outcomes for patients with LE compared with alternative local injections. Better results were observed with the use of LR-PRP than with the use of LP-PRP.


Assuntos
Plasma Rico em Plaquetas , Cotovelo de Tenista , Humanos , Leucócitos , Medição da Dor , Cotovelo de Tenista/terapia , Resultado do Tratamento
17.
Angew Chem Int Ed Engl ; 61(25): e202204117, 2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35384205

RESUMO

As a new path to "green" ammonia production, photoelectrochemical nitrate reduction reaction (PEC NO3 RR) is investigated for the first time. An Au-decorated ordered silicon nanowire (O_SiNW) array photocathode demonstrates 95.6 % of Faradaic efficiency (FE) to ammonia at 0.2 VRHE , which represents a more positive potential than the thermodynamic reduction potential of nitrate by utilizing photovoltage. The high FE is possible because both Si and Au surfaces are inactive for competing water reduction to hydrogen. The O_SiNW array structure is favorable to promote the PEC NO3 RR relative to planar Si or randomly-grown Si nanowire, by enabling the uniform distribution of small Au nanoparticles as an electrocatalyst and facilitating the mass transport during the reaction. The results demonstrate the feasibility of PEC nitrate conversion to ammonia and would motivate further studies and developments.

18.
Neuroimage ; 232: 117890, 2021 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-33617991

RESUMO

It is challenging to compare amyloid PET images obtained with different radiotracers. Here, we introduce a new approach to improve the interchangeability of amyloid PET acquired with different radiotracers through image-level translation. Deep generative networks were developed using unpaired PET datasets, consisting of 203 [11C]PIB and 850 [18F]florbetapir brain PET images. Using 15 paired PET datasets, the standardized uptake value ratio (SUVR) values obtained from pseudo-PIB or pseudo-florbetapir PET images translated using the generative networks was compared to those obtained from the original images. The generated amyloid PET images showed similar distribution patterns with original amyloid PET of different radiotracers. The SUVR obtained from the original [18F]florbetapir PET was lower than those obtained from the original [11C]PIB PET. The translated amyloid PET images reduced the difference in SUVR. The SUVR obtained from the pseudo-PIB PET images generated from [18F]florbetapir PET showed a good agreement with those of the original PIB PET (ICC = 0.87 for global SUVR). The SUVR obtained from the pseudo-florbetapir PET also showed a good agreement with those of the original [18F]florbetapir PET (ICC = 0.85 for global SUVR). The ICC values between the original and generated PET images were higher than those between original [11C]PIB and [18F]florbetapir images (ICC = 0.65 for global SUVR). Our approach provides the image-level translation of amyloid PET images obtained using different radiotracers. It may facilitate the clinical studies designed with variable amyloid PET images due to long-term clinical follow-up as well as multicenter trials by enabling the translation of different types of amyloid PET.


Assuntos
Amiloide/metabolismo , Compostos de Anilina/metabolismo , Encéfalo/metabolismo , Aprendizado Profundo , Tomografia por Emissão de Pósitrons/métodos , Estilbenos/metabolismo , Tiazóis/metabolismo , Idoso , Idoso de 80 Anos ou mais , Encéfalo/diagnóstico por imagem , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Compostos Radiofarmacêuticos/metabolismo
19.
Small ; 17(47): e2103861, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34553492

RESUMO

An array of SnO2 nanohelix structures is employed to fabricate a SnO2 helix@ZnFe2 O4 dendrite core-shell 3D heterostructure photoanode for photoelectrochemical (PEC) water splitting. The SnO2 helix provides triple critical functions to enhance the PEC performance of the photoanode. First, it scatters the incident light to achieve a higher light harvesting efficiency. Second, it provides a facile electron pathway as an electron transfer layer (ETL) while blocking hole transport to mitigate charge recombination in the bulk of ZnFe2 O4 . Finally, it becomes a template for the formation of ZnFe2 O4 dendrite nanostructure shell. The ZnFe2 O4 dendrite/SnO2 helix photoanode exhibits a remarkable increase in incident photon-to-electron conversion efficiency compared to unmodified ZnFe2 O4 with no ETL and modified one with "flat" SnO2 ETL. The surface of the ZnFe2 O4 /SnO2 helix photoanode is further modified with TiO2 passivation layer and NiFeOx oxygen evolution co-catalyst to achieve one of the best PEC performances among reported ZnFe2 O4 -based photoanodes.

20.
Hum Psychopharmacol ; 36(2): e2766, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33184922

RESUMO

OBJECTIVES: Whilst reduced signalling and gene expression related to gamma-aminobutyric acid (GABA) play a role in the presumed pathophysiology of schizophrenia, its origin is unclear. Studying asymptomatic individuals with high genetic liability to schizophrenia (AIs) would provide insights. Therefore, this study aimed to investigate the role of genetic liability in GABAergic dysfunction of schizophrenia by exploring in vivo GABA-A/benzodiazepine receptor (GABAR) availability in AIs. METHODS: A total of 10 AIs with multiple relatives diagnosed as schizophrenia and 11 healthy controls underwent [11C]flumazenil positron emission tomography and neurocognitive function tests. RESULTS: There was no significant difference in [11C]flumazenil availability based on the groups. GABAR availability in caudate nuclei had positive correlations with genetic liability of AIs. GABAR availability in caudate nuclei and verbal memory measures of AIs revealed positive correlations. Only the correlation between right caudate and short-term verbal memory survived multiple-comparison correction (p = 0.030). CONCLUSIONS: This study, for the first time, reports correlations between the genetic liability of schizophrenia and GABAR availability. Correlations between [11C]flumazenil binding in caudate of individuals with high genetic liability to schizophrenia suggests that the GABAergic dysfunction may arise from shared genetic factors and also that it may be responsible for cognitive impairment of AIs.


Assuntos
Flumazenil , Esquizofrenia , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Radioisótopos de Carbono , Humanos , Tomografia por Emissão de Pósitrons , Receptores de GABA-A/genética , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/genética , Ácido gama-Aminobutírico
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