Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 100
Filtrar
1.
Artigo em Inglês | MEDLINE | ID: mdl-38868706

RESUMO

Background and Aim: Endoscopic ultrasound shear wave elastography (EUS-SWE) can facilitate an objective evaluation of pancreatic fibrosis. Although it is primarily applied in evaluating chronic pancreatitis, its efficacy in assessing early chronic pancreatitis (ECP) remains underinvestigated. This study evaluated the diagnostic accuracy of EUS-SWE for assessing ECP diagnosed using the Japanese diagnostic criteria 2019. Methods: In total, 657 patients underwent EUS-SWE. Propensity score matching was used, and the participants were classified into the ECP and normal groups. ECP was diagnosed using the Japanese diagnostic criteria 2019. Pancreatic stiffness was assessed based on velocity (Vs) on EUS-SWE, and the optimal Vs cutoff value for ECP diagnosis was determined. A practical shear wave Vs value of ≥50% was considered significant. Results: Each group included 22 patients. The ECP group had higher pancreatic stiffness than the normal group (2.31 ± 0.67 m/s vs. 1.59 ± 0.40 m/s, p < 0.001). The Vs cutoff value for the diagnostic accuracy of ECP, as determined using the receiver operating characteristic curve, was 2.24m/s, with an area under the curve of 0.82 (95% confidence interval: 0.69-0.94). A high Vs was strongly correlated with the number of EUS findings (rs = 0.626, p < 0.001). Multiple regression analysis revealed that a history of acute pancreatitis and ≥2 EUS findings were independent predictors of a high Vs. Conclusions: There is a strong correlation between EUS-SWE findings and the Japanese diagnostic criteria 2019 for ECP. Hence, EUS-SWE can be an objective and invaluable diagnostic tool for ECP diagnosis.

2.
Physiol Rep ; 12(11): e16047, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38837588

RESUMO

Acetate is a short-chain fatty acid (SCFA) that is produced by microbiota in the intestinal tract. It is an important nutrient for the intestinal epithelium, but also has a high plasma concentration and is used in the various tissues. Acetate is involved in endurance exercise, but its role in resistance exercise remains unclear. To investigate this, mice were administered either multiple antibiotics with and without oral acetate supplementation or fed a low-fiber diet. Antibiotic treatment for 2 weeks significantly reduced grip strength and the cross-sectional area (CSA) of muscle fiber compared with the control group. Intestinal concentrations of SCFAs were reduced in the antibiotic-treated group. Oral administration of acetate with antibiotics prevented antibiotic-induced weakness of skeletal muscle and reduced CSA of muscle fiber. Similarly, a low-fiber diet for 1 year significantly reduced the CSA of muscle fiber and fecal and plasma acetate concentrations. To investigate the role of acetate as an energy source, acetyl-CoA synthase 2 knockout mice were used. These mice had a shorter lifespan, reduced skeletal muscle mass and smaller CSA of muscle fiber than their wild type littermates. In conclusion, acetate derived from the intestinal microbiome can contribute to maintaining skeletal muscle performance.


Assuntos
Acetatos , Microbioma Gastrointestinal , Camundongos Endogâmicos C57BL , Força Muscular , Músculo Esquelético , Animais , Acetatos/farmacologia , Acetatos/metabolismo , Músculo Esquelético/metabolismo , Músculo Esquelético/efeitos dos fármacos , Camundongos , Masculino , Força Muscular/efeitos dos fármacos , Microbioma Gastrointestinal/efeitos dos fármacos , Microbioma Gastrointestinal/fisiologia , Camundongos Knockout , Antibacterianos/farmacologia , Ácidos Graxos Voláteis/metabolismo , Fibras na Dieta/farmacologia , Fibras na Dieta/metabolismo
3.
Cureus ; 16(4): e57777, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38715994

RESUMO

BACKGROUND: The management of hypertriglyceridemia in patients with chronic kidney disease (CKD) is important. Pemafibrate, a novel selective peroxisome proliferator-activated receptor-alpha modulator with less toxic effects on liver and kidney function than those of other fibrates, has recently been approved for the treatment of patients with an estimated glomerular filtration rate (eGFR) lower than 30 mL/min/1.73 m2. However, the efficacy and safety of pemafibrate in patients with severe renal impairment have not yet been established. METHODS: This single-center, retrospective observational study included 12 outpatients with CKD and hypertriglyceridemia, who were newly started on low-dose pemafibrate (0.1 mg/day) treatment between December 2021 and May 2023 and whose eGFRs were less than 30 mL/min/1.73 m2 at baseline. Blood samples were collected before and at 12 weeks after pemafibrate treatment. RESULTS: After 12 weeks of treatment, the serum triglyceride level was significantly decreased, whereas the high-density lipoprotein cholesterol level was significantly increased. The serum alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transpeptidase, and uric acid levels were also significantly decreased, without worsening of the eGFR and serum creatinine levels. In the subgroup analysis, there were no significant differences in the changes in clinical parameters regardless of statin use and CKD stage at baseline. CONCLUSIONS: Low-dose pemafibrate administration in patients with severe renal impairment resulted in significant improvements in triglyceride, high-density lipoprotein cholesterol, and serum uric acid levels, and liver function, without adverse events.

4.
Artigo em Inglês | MEDLINE | ID: mdl-38796693

RESUMO

Seabuckthorn pulp oil (SBO) is used in beauty products because of its rich lipophilic substances with high nutraceutical and cosmeceutical potential. However, the mechanism through which SBO enhances skin elasticity remains unclear. Therefore, in this study, we examined the anti-photoaging activity of SBO in normal human dermal fibroblasts (NHDF) under ultraviolet (UV) irradiation. Pretreatment with SBO significantly suppressed UV-B-induced cell toxicity and collagen degradation, suggesting that SBO contains anti-photoaging substances. Further, palmitoleic acid (POA), the main component of SBO, maintained cell viability and collagen levels in UV-B-irradiated NHDF by suppressing the expression of matrix metalloproteinase 1 (MMP-1) and acted on the inhibition of p38 and JNK phosphorylation and nuclear translocation of nuclear factor-kappa B (NF-κB). These findings suggest the utility of SBO as an anti-photoaging agent.

5.
Chem Sci ; 15(6): 2007-2018, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38332815

RESUMO

Intracellular singlet oxygen (1O2) generation and detection help optimize the outcome of photodynamic therapy (PDT). Theranostics programmed for on-demand phototriggered 1O2 release and bioimaging have great potential to transform PDT. We demonstrate an ultrasensitive fluorescence turn-on sensor-sensitizer-RGD peptide-silica nanoarchitecture and its 1O2 generation-releasing-storing-sensing properties at the single-particle level or in living cells. The sensor and sensitizer in the nanoarchitecture are an aminomethyl anthracene (AMA)-coumarin dyad and a porphyrin or CdSe/ZnS quantum dots (QDs), respectively. The AMA in the dyad quantitatively quenches the fluorescence of coumarin by intramolecular electron transfer, the porphyrin or QD moiety generates 1O2, and the RGD peptide facilitates intracellular delivery. The small size, below 200 nm, as verified by scanning electron microscopy and differential light scattering measurements, of the architecture within the 1O2 diffusion length enables fast and efficient intracellular fluorescence switching by the tandem ultraviolet (UV)-visible or visible-near-infrared (NIR) photo-triggering. While the red emission and 1O2 generation by the porphyrin are continually turned on, the blue emission of coumarin is uncaged into 230-fold intensity enhancement by on-demand photo-triggering. The 1O2 production and release by the nanoarchitecture enable spectro-temporally controlled cell imaging and apoptotic cell death; the latter is verified from cytotoxic data under dark and phototriggering conditions. Furthermore, the bioimaging potential of the TCPP-based nanoarchitecture is examined in vivo in B6 mice.

6.
Cureus ; 16(1): e53153, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38420074

RESUMO

Serum levels of butyrylcholinesterase (BChE) are commonly used to assess liver function. Its levels have been reported to be significantly lower in patients undergoing dialysis. To the best of our knowledge, this is the first report of hereditary heterozygous BChE deficiency in a patient undergoing dialysis. Medical staff involved in the care of patients with BChE deficiency should be aware of anesthetic usage, because prolonged neuromuscular paralysis following the administration of succinylcholine or mivacurium may occur. However, in the heterozygotes, BChE activity is not completely absent. Therefore, differentiating patients undergoing dialysis is challenging. A 52-year-old man underwent living-related kidney transplantation for focal segmental glomerulosclerosis at 22 years of age. As the renal function gradually worsened, the patient began to receive combined hemodialysis and peritoneal dialysis therapy. No problems with anesthesia were observed in past surgeries. The patient's BChE levels fluctuated between 76 and 170 U/L (reference range: 198-495 U/L); however, they had never been previously investigated. We suspected hereditary heterozygous BChE deficiency because the patient's sister was also diagnosed with it. DNA sequencing revealed a heterozygous missense mutation (Gly365Arg) and a K-variant (Ala539Thr). Patients on dialysis with low serum BChE levels often present with low albumin levels which may be overlooked as malnutrition. Thus, BChE deficiency should be suspected in patients on dialysis with unexplained low serum BChE levels. In the case of heterozygous BChE deficiency, the reference value is low, and continuous monitoring is crucial.

7.
Nanoscale ; 16(10): 5107-5114, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38227491

RESUMO

Zero-dimensional hybrid copper(I) halides (HCHs) are attractive due to their interesting photoluminescence (PL) properties and the high abundance and low toxicity of copper. In this study, we report green-red dual emission from rhombic 1-butyl-1-methyl piperidinium copper bromide [(Bmpip)2Cu2Br4] microcrystals (MCs) prepared on borosilicate glass. The structure and elemental composition of the MCs are characterized by single crystal X-ray diffraction analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Interestingly, MCs prepared on an ITO-coated glass plate show an intense green emission compared to the dual emission on a bare glass or plastic substrate. Furthermore, the intensity of the green emission from the MC is enormously increased by powdering using a conductive material, suggesting the deactivation of the red-emitting state by a charge transfer interaction with the conductor. These findings open a new strategy to suppress the self-trapping of excitons by longitudinal optical phonons and control the dual emitting states in HCHs.

8.
Biol Pharm Bull ; 47(1): 138-144, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38171773

RESUMO

Sjögren's syndrome (SS) is an autoimmune disorder characterized by oral dryness that is primarily attributed to tumor necrosis factor alpha (TNF-α)-mediated reduction in saliva production. In traditional Chinese medicine, goji berries are recognized for their hydrating effect and are considered suitable to address oral dryness associated with Yin deficiency. In the present study, we used goji berry juice (GBJ) to investigate the potential preventive effect of goji berries on oral dryness caused by SS. Pretreatment of human salivary gland cells with GBJ effectively prevented the decrease in aquaporin-5 (AQP-5) mRNA and protein levels induced by TNF-α. GBJ also inhibited histone H4 deacetylation and suppressed the generation of intracellular reactive oxygen species (ROS). Furthermore, GBJ pretreatment reserved mitochondrial membrane potential and suppressed the upregulation of Bax and caspase-3, indicating that GBJ exerted an antiapoptotic effect. These findings suggest that GBJ provides protection against TNF-α in human salivary gland cells and prevents the reduction of AQP-5 expression on the cell membrane. Altogether, these results highlight the potential role of GBJ in preventing oral dryness caused by SS.


Assuntos
Lycium , Síndrome de Sjogren , Xerostomia , Humanos , Fator de Necrose Tumoral alfa/metabolismo , Lycium/metabolismo , Glândulas Salivares/metabolismo , Glândulas Salivares/patologia , Xerostomia/induzido quimicamente , Xerostomia/prevenção & controle , Xerostomia/complicações , Síndrome de Sjogren/complicações , Síndrome de Sjogren/metabolismo , Síndrome de Sjogren/patologia , Aquaporina 5/genética
9.
Commun Biol ; 7(1): 27, 2024 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-38182890

RESUMO

Tumor tissues consist of heterogeneous cells that originate from stem cells; however, their cell fate determination program remains incompletely understood. Using patient-derived organoids established from patients with advanced colorectal cancer (CRC), we evaluated the potential of olfactomedin 4 (OLFM4)+ stem cells to produce a bifurcated lineage of progenies with absorptive and secretory properties. In the early phases of organoid reconstruction, OLFM4+ cells preferentially gave rise to secretory cells. Additionally, we found that Paneth-like cells, which do not exist in the normal colon, were induced in response to Notch signaling inhibition. Video recordings of single OLFM4+ cells revealed that organoids containing Paneth-like cells were effectively propagated and that their selective ablation led to organoid collapse. In tumor tissues, Paneth-like cells were identified only in the region where tumor cells lost cell adhesion. These findings indicate that Paneth-like cells are directly produced by OLFM4+ stem cells and that their interaction contributes to tumor formation by providing niche factors. This study reveals the importance of the cell fate specification program for building a complete tumor cellular ecosystem, which might be targeted with novel therapeutics.


Assuntos
Neoplasias Colorretais , Ecossistema , Humanos , Células-Tronco , Proliferação de Células , Organoides , Fator Estimulador de Colônias de Granulócitos
10.
Intern Med ; 63(3): 433-438, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-37258157

RESUMO

We herein report three cases of steroid-resistant nephrotic syndrome successfully treated with low-density lipoprotein apheresis (LDL-A). All patients were treated with a combination of steroids, cyclosporine, and LDL-A. In all cases, the serum concentrations of LDL, total and high-density lipoprotein cholesterol, and triglycerides were significantly lowered following LDL-A administration. Furthermore, the estimated LDL receptor activity increased, while both serum LDL and total cholesterol levels decreased, suggesting that LDL-A increases LDL receptor activity by driving changes in serum cholesterol concentration. This case series suggests that LDL-A increases LDL receptor activity, which may improve the intracellular uptake of cyclosporine.


Assuntos
Remoção de Componentes Sanguíneos , Glomerulosclerose Segmentar e Focal , Síndrome Nefrótica , Humanos , Síndrome Nefrótica/tratamento farmacológico , Lipoproteínas LDL/uso terapêutico , Ciclosporina/uso terapêutico , Apolipoproteínas/uso terapêutico , Receptores de LDL , Progressão da Doença , Colesterol
11.
CEN Case Rep ; 2023 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-38135868

RESUMO

Fabry disease is an X-linked hereditary disorder caused by deficient α-galactosidase A (GLA) activity. Patients with Fabry disease are often treated with enzyme replacement therapy (ERT). However, ERT often induces the formation of neutralizing antidrug antibodies (ADAs), which may impair the therapeutic efficacy. Here, we report the case of a 32-year-old man with Fabry disease and resultant neutralizing ADAs who was treated by switching from agalsidase-α to agalsidase-ß. We monitored biomarkers, such as plasma globotriaosylsphingosine (lyso-Gb3), urinary globotriaosylceramide (Gb3), urinary mulberry bodies, renal and cardiac parameters, and disease severity during the treatment period. Although plasma lyso-Gb3 and urinary Gb3 levels quickly decreased within two months after the initiation of ERT with agalsidase-α, they gradually increased thereafter. The urinary mulberry bodies continued to appear. Both the ADA titer and serum mediated GLA inhibition rates started to increase after two months. Moreover, 3.5 years after ERT, the vacuolated podocyte area in the renal biopsy decreased slightly from 23.1 to 18.9%. However, plasma lyso-Gb3 levels increased, and urinary Gb3, mulberry body levels, and ADA titers remained high. Therefore, we switched to agalsidase-ß which reduced, but did not normalize, plasma lyso-Gb3 levels and stabilized renal and cardiac parameters. Disease severity was attenuated. However, urinary Gb3 and mulberry body levels did not decrease noticeably in the presence of high ADA titers. The kidneys take up a small amount of the administered recombinant enzyme, and the clearance of Gb3 that has accumulated in the kidney may be limited despite the switching from agalsidase-α to agalsidase-ß.

12.
Sci Rep ; 13(1): 22217, 2023 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-38097649

RESUMO

Osteoprotegerin (OPG) is a secreted cytokine that functions as a decoy receptor for receptor activator of nuclear factor kappa-B (RANK) ligand (RANKL). Anti-RANKL treatment for bone metastasis has been widely accepted for solid tumors. However, the mechanism of OPG-RANKL-RANK signaling in systemic colorectal cancer (CRC) metastasis remains unclear. In this study, we investigated the relevance and function of OPG expression in CRC liver metastasis. First, we performed in silico analysis using The Cancer Genome Atlas public database and found that lower OPG expression in CRC was associated with poor overall survival. Immunohistochemistry analyses using resected specimen from patients with CRC in our institute confirmed the result. Patient-matched primary CRC and liver metastases showed a significant downregulation of OPG expression in metastatic lesions. In CRC cell lines, OPG expression did not suppress cell proliferation and migration. However, OPG expression inhibited macrophage migration by suppressing the RANKL-RANK pathway. Moreover, in vivo mouse liver metastasis models showed that OPG expression in CRC cells suppressed liver metastases. In addition, treatment with an anti-RANKL neutralizing antibody also suppressed liver metastases. These results showed that downregulation of OPG expression in CRC cells promotes liver metastasis by activating tumor-associated macrophage, which can become a candidate for targeted therapy with anti-RANKL neutralizing antibody for CRC liver metastasis.


Assuntos
Neoplasias Colorretais , Neoplasias Hepáticas , Animais , Humanos , Camundongos , Anticorpos Neutralizantes/metabolismo , Neoplasias Colorretais/genética , Regulação para Baixo , Neoplasias Hepáticas/genética , Osteoprotegerina/genética , Osteoprotegerina/metabolismo , Ligante RANK/genética , Ligante RANK/metabolismo , Receptor Ativador de Fator Nuclear kappa-B/genética , Receptor Ativador de Fator Nuclear kappa-B/metabolismo , Macrófagos Associados a Tumor/metabolismo
13.
Chem Commun (Camb) ; 59(93): 13831-13834, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37859494

RESUMO

Rationally assembled supramolecular structures of organic chromophores or semiconductor nanomaterials show excitonic properties different from individual molecules or nanoparticles. We report polymer-assisted assembly formation and thermal modulation of excitonic recombination in self-assembled formamidinium lead bromide perovskite quantum dots.

14.
Nihon Shokakibyo Gakkai Zasshi ; 120(10): 845-851, 2023.
Artigo em Japonês | MEDLINE | ID: mdl-37821374

RESUMO

A 78-year-old female patient presented to our hospital with abdominal pain and melena. Abdominal ultrasonography detected a multiple concentric ring sign and retrograde invagination mass near the hepatic flexure. Colonoscopy revealed a 40-mm diameter type 1 tumor in the transverse colon near the splenic flexure, and the biopsy specimen demonstrated a well-differentiated adenocarcinoma. Retrograde intussusception due to transverse colon cancer was diagnosed, and laparoscopic transverse colon resection with lymph node dissection was performed. The resected specimen revealed a 48×40mm diameter type 1 tumor in the transverse colon and was diagnosed as pT2N0M0 pStage I. Contrast-enhanced computed tomography was unavailable, but real-time assessment of the invaginated mass and bowel blood flow was possible by abdominal ultrasonography, which was useful in determining the diagnosis and treatment strategy.


Assuntos
Colo Transverso , Neoplasias do Colo , Intussuscepção , Feminino , Humanos , Idoso , Colo Transverso/diagnóstico por imagem , Colo Transverso/cirurgia , Colo Transverso/patologia , Intussuscepção/diagnóstico por imagem , Intussuscepção/etiologia , Intussuscepção/cirurgia , Neoplasias do Colo/complicações , Neoplasias do Colo/diagnóstico por imagem , Neoplasias do Colo/cirurgia , Abdome/patologia , Colonoscopia
15.
Cureus ; 15(8): e43510, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37727178

RESUMO

BACKGROUND: Japanese people traditionally consume high quantities of salt. This study aimed to investigate the effects of educating patients with chronic kidney disease (CKD) on simple methods for reducing their daily dietary salt intake. METHODS: This single-center, retrospective observational study included 115 outpatients with CKD at Kawashima Hospital (Tokushima, Japan). One physician routinely recommended that patients should reduce their salt intake and provided tips for salt restriction. The physician estimated the patients' daily salt intake using spot urine samples at each medical examination (education group; n = 61). The other physicians' outpatients only received dietary guidance on recommended salt intake (control group; n = 54). The estimated 24-hour urinary sodium excretion (24hUNaV) and 24-hour potassium excretion (24hUKV) were calculated using Tanaka's equation. RESULTS: Estimated 24hUNaV was positively correlated with body mass index (BMI), estimated 24hUKV, and urinary Na/K ratio. The patients in the education group were younger and had a lower BMI, higher estimated glomerular filtration rate, and lower systolic blood pressure (SBP). Using 38 pairs of patients obtained by propensity score matching with these variables, estimated 24hUNaV, estimated 24hUKV, and diastolic blood pressure (DBP) after one year were significantly reduced in the education group. CONCLUSION: A simple salt reduction education may reduce salt intake in outpatients with CKD.

16.
Nanomaterials (Basel) ; 13(16)2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37630877

RESUMO

This paper demonstrates the in situ sinter bonding of Ag microparticle pastes to a Si substrate via the temporal formation and decomposition of Ag carboxylate on the surface of Ag microparticles. This was proposed via the investigation of Ag sinter bonding using the redox reaction between Ag2O and ethylene glycol, which achieved a bonding strength above 30 MPa even for the bonding temperature at 220 °C. Thermal analysis was used to identify the product of the redox reaction between Ag2O and ethylene glycol and determine the bonding temperature because the final reaction facilitates the interfacial sinter bonding with the substrate. Fourier-transform infrared spectroscopy and nuclear magnetic resonance results indicated the in situ formation of Ag salts of carboxylic acids, such as Ag oxalate on the surface of Ag microparticles. Therefore, the sinter bonding process enabled by the in situ formation and subsequent decomposition of these Ag salts was investigated using Ag microparticles and oxalic acid. Observations of the surface and interfacial morphology of the Ag particles after heating revealed the formation of Ag nanoparticles on the surfaces of the microparticles and the formation of sintering necks between the particles. The bonding experiments demonstrated a significant increase in strength with the addition of oxalic acid to the Ag paste due to the enhanced interfacial sinter bonding with the substrate. The in situ formation and decomposition of Ag salts are promising strategies for improving sintered bonds in electronic devices because they can provide enhanced localized sinter bonding using stable insert materials.

17.
ACS Appl Mater Interfaces ; 15(34): 41081-41091, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37581484

RESUMO

Halide vacancies cause lattice degradation and nonradiative losses in halide perovskites. In this study, we strategically fill bromide vacancies in CsPbBr3 perovskite nanocrystals with NaBr, KBr, or CsBr at the organic-aqueous interface for hydrophobic ligand-capped nanocrystals or in a polar solvent (2-propanol) for amphiphilic ligand-capped nanocrystals. Energy-dispersive X-ray spectra, powder X-ray diffraction data, and scanning transmission electron microscopy images help us confirm vacancy filling and the structures of samples. The bromide salts increase the photoluminescence quantum yield (98 ± 2%) of CsPbBr3 by decreasing the nonradiative decay rate. Single-particle studies show the quantum yield increase originates from the poorly luminescent nanocrystals becoming highly luminescent after filling vacancies. Furthermore, we tune the optical band gap (ultraviolet-visible-near-infrared) of the hydrophobic ligand-capped nanocrystals by halide exchange at the toluene-water interface using saturated NaCl or NaI solutions, which completes in about 60 min under continuous mixing. In contrast, the amphiphilic ligand accelerates the halide exchange in 2-propanol, suggesting ambipolar functional groups speed up the ion-exchange reaction. The bromide vacancy-filled or halide-exchanged samples in a toluene-water biphasic solvent show higher stability than amphiphilic ligand-capped samples in 2-propanol. This strategy of defect passivation, ion exchange, and ligand chemistry to improve quantum yields and tune band gaps of halide perovskite nanocrystals can be promising for designing stable and water-soluble perovskite samples for solar cells, light-emitting diodes, photodetectors, and photocatalysts.

18.
Small ; 19(48): e2304900, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37491792

RESUMO

Halide perovskites are ideal for next-generation optical devices and photovoltaics. Although perovskite single-crystals show reproducible optoelectronic properties, significant variations in the crystal size, anisotropy, density, defects, photoluminescence (PL), and carrier lifetime affect the sample properties and device performances. Homogenous size and shape FA/MAPbBr3 single microcrystals (MCs) with controlled edge lengths, crystal densities, PL lifetimes, and PL intensities are prepared by thermodynamically controlling and kinetically separating the crystal nucleation-growth processes using optimum N-cyclohexyl-2-pyrrolidone (CHP) concentration. The crystal growth kinetics at different CHP concentrations and temperatures are estimated spectroscopically by measuring the concentration of Pb (II). High-density cubic MCs with a homogenous size distribution, high PL intensities, and long PL lifetimes are obtained within minutes at high temperatures by the controlled addition of the pyrrolidone derivative. Conversely, the crystal size nonlinearly increases with time at low temperatures. The isotropically grown high-density single crystals at controlled nucleation-growth rates at 190 °C with 20% CHP show the highest PL intensity and the longest PL lifetimes. This method offers thermodynamic and kinetic control of perovskite single-crystal growth with shape control.

19.
Tohoku J Exp Med ; 261(1): 69-73, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37495524

RESUMO

X-linked Alport syndrome is a hereditary progressive renal disease resulting from the disruption of collagen α3α4α5 (IV) heterotrimerization caused by pathogenic variants in the COL4A5 gene. This study aimed to report a male case of X-linked Alport syndrome with a mild phenotype accompanied by an atypical expression pattern of type IV collagen α5 [α5 (IV)] chain in glomerulus. A 38-year-old male presented with proteinuria (2.3 g/day) and hematuria. He has been detected urinary protein and occult blood since childhood. A renal biopsy was performed at the age of 29 years; however, a diagnosis of Alport syndrome was not considered. A renal biopsy 9 years later revealed diffuse thinning and lamellation of the glomerular basement membrane. Α staining for α5 (IV) revealed a normal expression pattern in the glomerular basement membrane and a complete negative expression in Bowman's capsule and distal tubular basement membrane. Using next-generation sequencing, we detected a COL4A5 missense variant within exon 35 (NM_000495.5: c.3088G>A, p. G1030S). The possibility of X-linked Alport syndrome should be considered when negative expression of α5 (IV) staining on Bowman's capsule was observed.


Assuntos
Nefrite Hereditária , Masculino , Humanos , Criança , Adulto , Nefrite Hereditária/genética , Nefrite Hereditária/metabolismo , Nefrite Hereditária/patologia , Colágeno Tipo IV/genética , Cápsula Glomerular/metabolismo , Cápsula Glomerular/patologia , Membrana Basal Glomerular/patologia , Éxons
20.
Small ; 19(32): e2303496, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37170667

RESUMO

Supramolecularly assembled high-order supercrystals (SCs) help control the dielectric, electronic, and excitonic properties of semiconductor nanocrystals (NCs) and quantum dots (QDs). Ligand-engineered perovskite NCs (PNCs) assemble into SCs showing shorter excitonic lifetimes than strongly dielectric PNC films showing long photoluminescence (PL) lifetimes and long-range carrier diffusion. Monodentate to bidentate ligand exchange on ≈ 8 nm halide perovskite (APbX3 ; A:Cs/MA, X:Br/I) PNCs generates mechanically stable SCs with close-packed lattices, overlapping electronic wave functions, and higher dielectric constant, providing distinct excitonic properties from single PNCs or PNC films. From Fast Fourier Transform (FFT) images, time-resolved PL, and small-angle X-ray scattering, structurally and excitonically ordered large SCs are identified. An Sc shows a smaller spectral shift (<35 meV) than a PNC film (>100 meV), a microcrystal (>100 meV), or a bulk crystal (>100 meV). Also, the exciton lifetime (<10 ns) of an SC is excitation power-independent in the single exciton regime 〈N〉<1, comparable to an isolated PNC. Therefore, bidentate-ligand-assisted SCs help overcome delayed exciton or carrier recombination in halide perovskite nanocrystal assemblies or films.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA