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1.
Biophys J ; 2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38946141

RESUMO

Raf kinases play key roles in signal transduction in cells for regulating proliferation, differentiation, and survival. Despite decades of research into functions and dynamics of Raf kinases with respect to other cytosolic proteins, understanding Raf kinases is limited by the lack of their full-length structures at the atomic resolution. Here, we present the first model of the full-length CRaf kinase obtained from Artificial Intelligence/Machine Learning (AI/ML) algorithms with a converging ensemble of structures simulated by large-scale temperature replica exchange simulations. Our model is validated by comparing simulated structures with the latest Cryo-EM structure detailing close contacts among three key domains and regions of the CRaf. Our simulations reveal potentially new epitopes of intra-molecule interactions within the CRaf and reveal a dynamical nature of CRaf kinases, in which the three domains can move back and forth relative to each other for regulatory dynamics. The dynamical conformations are then used in a docking algorithm to shed insight into the paradoxical effect caused by Vemurafenib in comparison with a paradox breaker PLX7904. We propose a model of Raf-heterodimer/KRas-dimer as a signalosome based on the dynamics of the full-length CRaf.

2.
Nat Prod Res ; : 1-6, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38728614

RESUMO

One new compound, styrene dimer-type listeanol-4-O-α-ʟ-rhamnopyranosyl-(1→4)-ß-ᴅ-glucopyranoside (1), and four known compounds namely listeanol (2), isorhapotigenin (3), genetifolin E (4), gnetifolin K (5) were isolated from the methanolic extract from the aerial part of the Gnetum montanum Markgr. in Viet Nam. Their chemical structures were determined by modern spectroscopic methods (NMR and HR-ESI-MS) and comparison with those of published data. These compounds were evaluated for their anti-inflammatory and cytotoxic activities. Among them, compound 3 exhibited the NO inhibitory production on the RAW264.7 cell line, and inhibited the HepG2 cell line with respective IC50 values of 79.88 ± 5.51 (µg/mL) (L-NMMA 7.90 ± 0.63 µg/mL), and 63.48 ± 3.63 (µg/mL) (Ellipticine 0.40 ± 0.01 µg/mL).

3.
J Epidemiol Popul Health ; 72(4): 202519, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38703754

RESUMO

INTRODUCTION: Oral hygiene is a crucial factor in oral health, especially in children. To increase the awareness of oral care behaviour among children, oral care motivation plays a critical role in daily dental practices. Therefore, this cross-sectional study was conducted to investigate the current oral hygiene status and evaluate the association between oral care motivation and oral hygiene index in 7-9-year-old children at Primary School in Hanoi, Vietnam. METHODS: Clinical examinations were performed on 200 randomly selected children to assess the Simplified Oral Hygiene Index (OHI-S). Face-to-face interviews were applied to record students' intrinsic and extrinsic motivation for oral care through a questionnaire, which consisted of questions regarding demographic characteristics and oral care motivation. Data were analyzed using STATA 15.0 software and a p-value < 0.05 was statistically significant. RESULTS: The mean OHI-S score was 2.48 ± 0.72. Good and fair oral hygiene were observed in 7.5 % and 66 % of participants, respectively. Students' motivation for dental care was predominantly extrinsic, with a mean score of 15.87 ± 1.322. Higher motivation in dental care is statistically significantly associated with oral hygiene index score (Coef=-0.27). CONCLUSION: These results indicate that students with intrinsic motivation exhibit better oral hygiene practices. Consequently, strengthening oral health educational programs in primary schools based on intrinsic motivation could be helped improve the oral hygiene status and oral care behaviours of children.

4.
Liver Transpl ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38713020

RESUMO

Psychiatric disorders after liver transplantation (LT) are associated with worse patient and graft outcomes, which may be amplified by inadequate treatment. We aimed to characterize the burden of psychiatric disorders, treatment patterns, and associated financial burden among liver transplantation recipients (LTRs). IQVIA PharMetrics (R) Plus for Academics-a large health plan claims database representative of the commercially insured US population-was used to identify psychiatric diagnoses among adult LTRs and assess treatment. Multivariable logistic regression analysis identified factors associated with post-LT psychiatric diagnoses and receipt of pharmacotherapy. Patient financial liability was estimated using adjudicated medical/pharmacy claims for LTRs with and without psychiatric diagnoses. Post-LT psychiatric diagnoses were identified in 395 (29.5%) of 1338 LTRs, of which 106 (26.8%) were incident cases. Treatment varied, with 67.3% receiving pharmacotherapy, 32.1% psychotherapy, 21.0% combination therapy, and 21.5% no treatment. Among 340 LTRs on psychotropic medications before transplant, 24% did not continue them post-LT. Post-LT psychiatric diagnoses were independently associated with female sex, alcohol-associated liver disease (ALD), prolonged LT hospitalization (>2 wk), and pre-LT psychiatric diagnosis. Incident psychiatric diagnoses were associated with female sex, ALD, and prolonged LT hospitalization. Patients with a post-LT psychiatric diagnosis had higher rates of hospitalization (89.6% vs. 81.5%, p <0.001) and financial liability (median $5.5K vs. $4.6K USD, p =0.006). Having a psychiatric diagnosis post-LT was independently associated with experiencing high financial liability >$5K. Over 1 in 4 LTRs had a psychiatric diagnosis in a large national cohort, yet nearly a quarter received no treatment. LTRs with psychiatric diagnoses experienced increased health care utilization and higher financial liability. Sociodemographic and clinical risk factors could inform high-risk subgroups who may benefit from screening and mitigation strategies.

5.
JACS Au ; 4(4): 1458-1470, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38665661

RESUMO

Our study reveals the underlying principles governing the passive membrane permeability in three large N-methylated macrocyclic peptides (N-MeMPs): cyclosporine A (CycA), Alisporivir (ALI), and cyclosporine H (CycH). We determine a series of conformers required for robust passive membrane diffusion and those relevant to other functions, such as binding to protein targets or intermediates, in the presence of solvent additives. We investigate the conformational interconversions and establish correlations with the membrane permeability. Nuclear magnetic resonance (NMR) and cyclic ion-mobility spectrometry-mass spectrometry (cIMS-MS) are employed to characterize conformational heterogeneity and identify cis-amides relevant for good membrane permeability. In addition, ion mobility selected cIMS-MS and infrared (IR) multiple-photon dissociation (IRMPD) spectroscopy experiments are conducted to evaluate the energy barriers between conformations. We observe that CycA and ALI, both cyclosporines with favorable membrane permeabilities, display multiple stable and well-defined conformers. In contrast, CycH, an epimer of CycA with limited permeability, exhibits fewer and fewer stable conformers. We demonstrate the essential role of the conformational shift from the aqueous cis MeVal11-MeBmt1 state (A1) to the closed conformation featuring cis MeLeu9-MeLeu10 (C1) in facilitating membrane permeation. Additionally, we highlight that the transition from A1 to the all-trans open conformation (O1) is specifically triggered by the presence of CaCl2. We also capture a set of conformers with cis Sar3-MeLeu4, MeLeu9-MeLeu10, denoted as I. Conformationally selected cIMS-MS and IRMPD data of [CycA+Ca]2+ show immediate repopulation of the original population distribution, suggesting that CaCl2 smooths out the energy barriers. Finally, our work presents an improved sampling molecular dynamics approach based on a refined force field that not only consistently and accurately captures established conformers of cyclosporines but also exhibits strong predictive capabilities for novel conformers.

6.
Prog Mol Biol Transl Sci ; 204: 97-107, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38458745

RESUMO

ß-thalassemia is an autosomal recessive disease, caused by one or more mutations in the ß-globin gene that reduces or abolishes ß-globin chain synthesis causing an imbalance in the ratio of α- and ß-globin chain. Therefore, the ability to target mutations will provide a good result in the treatment of ß-thalassemia. RNA therapeutics represents a promising class of drugs inclusive antisense oligonucleotides (ASO), small interfering RNA (siRNA), microRNA (miRNA) and APTAMER have investigated in clinical trials for treatment of human diseases as ß-thalassemia; Especially, ASO therapeutics can completely treat ß-thalassemia patients by the way of making ASO infiltrating through erythrocyte progenitor cells, migrating to the nucleus and hybridizing with abnormal splicing sites to suppress an abnormal splicing pattern of ß-globin pre-mRNA. As a result, the exactly splicing process is restored to increase the expression of ß-globin which increases the amount of mature hemoglobin of red blood cells of ß-thalassemia patients. Furthermore, current study demonstrates that RNA-based therapeutics get lots of good results for ß-thalassemia patients. Then, this chapter focuses on current advances of RNA-based therapeutics and addresses current challenges with their development and application for treatment of ß-thalassemia patients.


Assuntos
Talassemia beta , Humanos , Talassemia beta/genética , Talassemia beta/terapia , RNA/metabolismo , RNA Mensageiro/genética , Splicing de RNA/genética , Globinas beta/genética , Globinas beta/metabolismo
7.
Natl Sci Rev ; 11(3): nwae029, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38410825

RESUMO

Stereospecific recognition of chiral molecules plays a crucial role in biological systems. The µ-opioid receptor (MOR) exhibits binding affinity towards (-)-morphine, a well-established gold standard in pain management, while it shows minimal binding affinity for the (+)-morphine enantiomer, resulting in a lack of analgesic activity. Understanding how MOR stereoselectively recognizes morphine enantiomers has remained a puzzle in neuroscience and pharmacology for over half-a-century due to the lack of direct observation techniques. To unravel this mystery, we constructed the binding and unbinding processes of morphine enantiomers with MOR via molecular dynamics simulations to investigate the thermodynamics and kinetics governing MOR's stereoselective recognition of morphine enantiomers. Our findings reveal that the binding of (-)-morphine stabilizes MOR in its activated state, exhibiting a deep energy well and a prolonged residence time. In contrast, (+)-morphine fails to sustain the activation state of MOR. Furthermore, the results suggest that specific residues, namely D1142.50 and D1473.32, are deprotonated in the active state of MOR bound to (-)-morphine. This work highlights that the selectivity in molecular recognition goes beyond binding affinities, extending into the realm of residence time.

8.
Prog Mol Biol Transl Sci ; 203: 99-114, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38360008

RESUMO

Ribonucleic acid (RNA) therapeutics have significantly used RNA-based drugs to the prevention and treatment of diseases as effective messenger RNA-based vaccines in response to the COVID-19 pandemic. The RNA therapeutics with five classes including antisense oligonucleotide, small interfering RNA, microRNA, APTAMER and messenger RNAs are being quickly developed to treat various human diseases as neurological disease, cardiovascular disease, genetic and rare disease, cancer disease, coronavirus disease… which cannot be treated by other conventional drugs as small molecule-based drugs and antibodies. Therefore, the discovery of these RNA therapeutics created a new avenue for treatment of various human diseases. This chapter demonstrates the history of important discoveries in RNA biology and their impact on key developments in RNA therapeutics as well as the advantages of RNA therapeutics; RNA therapeutics describes the action mechanisms and examples of RNA-based drugs approved for treatment of various disease; and RNA therapeutics discusses delivery methods for RNA therapeutics to target organs and cells. In conclusion, this chapter is designed to offer an updated important development and advance of RNA therapeutics for the prevention and treatment of various human diseases.


Assuntos
MicroRNAs , RNA , Humanos , Pandemias , MicroRNAs/genética , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/uso terapêutico , Oligonucleotídeos Antissenso/uso terapêutico , RNA Mensageiro
9.
Nat Prod Res ; 38(4): 601-606, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-36924396

RESUMO

Two new vernonioside K (1) and vernonioside L (2) and four known Δ7,9(11) stigmastane-type steroidal saponins-vernonioside B2 (3), vernoniacum B (4), vernonioside B1 (5), and vernoamyoside A (6)-were isolated from the leaves of Vernonia amygdalina. Their structures were determined by comprehensive spectroscopic analysis with one-dimensional nuclear magnetic resonance, two-dimensional nuclear magnetic resonance, and high-resolution mass spectrometry. All isolated compounds (1-6) were evaluated to determine their inhibitory effects on α-glucosidase and xanthine oxidase. Among them, two new compounds 1 and 2 showed significant inhibition of α-glucosidase with IC50 values of 78.56 ± 7.28 and 14.74 ± 1.57 (µM), respectively, comparable with acarbose as a positive control (127.53 ± 1.73 µM); none of these compounds inhibited xanthine oxidase activity. Compounds 1 and 2 are promising candidates for the development of antidiabetic agents from natural sources.


Assuntos
Saponinas , Vernonia , alfa-Glucosidases , Vernonia/química , Xantina Oxidase , Saponinas/farmacologia , Saponinas/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Esteroides/química
10.
Sci Total Environ ; 912: 169113, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38065499

RESUMO

Landslides endanger lives and public infrastructure in mountainous areas. Monitoring landslide traces in real-time is difficult for scientists, sometimes costly and risky because of the harsh terrain and instability. Nowadays, modern technology may be able to identify landslide-prone locations and inform locals for hours or days when the weather worsens. This study aims to propose indicators to detect landslide traces on the fields and remote sensing images; build deep learning (DL) models to identify landslides from Sentinel-2 images automatically; and apply DL-trained models to detect this natural hazard in some particular areas of Vietnam. Nine DL models were trained based on three U-shaped architectures, including U-Net, U2-Net, and U-Net3+, and three options of input sizes. The multi-temporal Sentinel-2 images were chosen as input data for training all models. As a result, the U-Net, using an input image size of 32 × 32 and a performance of 97 % with a loss function of 0.01, can detect typical landslide traces in Vietnam. Meanwhile, the U-Net (64 × 64) can detect more considerable landslide traces. Based on multi-temporal remote sensing data, a different case study in Vietnam was chosen to see landslide traces over time based on the trained U-Net (32 × 32) model. The trained model allows mountain managers to track landslide occurrences during wet seasons. Thus, landslide incidents distant from residential areas may be discovered early to warn of flash floods.

11.
Am J Trop Med Hyg ; 110(1): 142-149, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38109767

RESUMO

Flea-borne typhus (FBT), also referred to as murine typhus, is an acute febrile disease in humans caused by the bacteria Rickettsia typhi. Currently, cases of FBT are reported for public health surveillance purposes (i.e., to detect incidence and outbreaks) in a few U.S. states. In California, healthcare providers and testing laboratories are mandated to report to their respective local public health jurisdictions whenever R. typhi or antibodies reactive to R. typhi are detected in a patient, who then report cases to state health department. In this study, we characterize the epidemiology of flea-borne typhus cases in California from 2011 to 2019. A total of 881 cases were reported during this period, with most cases reported among residents of Los Angeles and Orange Counties (97%). Demographics, animal exposures, and clinical courses for case patients were summarized. Additionally, spatiotemporal cluster analyses pointed to five areas in southern California with persistent FBT transmission.


Assuntos
Sifonápteros , Tifo Endêmico Transmitido por Pulgas , Tifo Epidêmico Transmitido por Piolhos , Animais , Camundongos , Humanos , Tifo Endêmico Transmitido por Pulgas/diagnóstico , Rickettsia typhi , California/epidemiologia , Sifonápteros/microbiologia
12.
Liver Transpl ; 2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-38108824

RESUMO

Liver transplantation (LT) is lifesaving for patients with cirrhosis; however, the resultant financial burden to patients has not been well characterized. We aimed to provide a nationally representative portrayal of patient financial burden after LT. Adult recipients of LT from 2006 to 2021 were identified using IQVIA PharMetrics® Plus for Academics-a large nationally representative claims database of commercially insured Americans. Patient financial liability (ie, what patients owe) was estimated using the difference between allowed and paid costs for adjudicated medical/pharmacy claims. Descriptive statistics were provided stratified by the financial liability group within 1 year after LT. Multivariable logistic regression modeling identified factors associated with high/extreme liability adjusting for covariates. Potential indirect costs of post-LT care were estimated based on hourly wages lost for care. Among 1412 recipients of LT, financial liability was heterogeneous-~3% had no liability and 21% had extreme liability > $10K for 1-year post-LT care; most (69%) paid between $1 and 10K, with 48% having liability >$5K. Factors associated with >$5K liability included older age, insurance/enrollment type, US region, history of HCC, and simultaneous liver-kidney transplant (for liability >$10K). Medication costs comprised ~30% of outpatient financial liability. Potential indirect costs from wages lost were $2,201-$6,073 per person, depending on an hourly wage. In a large national cohort of commercially insured recipients of LT, financial liability was highly variable across sociodemographic and clinical characteristics; nearly 1 out of 2 recipients of LT owed >$5K for 1 year of post-LT care. Transplant programs should help patients anticipate potential costs and identify vulnerable populations who would benefit from enhanced financial counseling.

13.
Int J Gen Med ; 16: 4919-4930, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37928958

RESUMO

Background: An association between heart rate variability (HRV) and cardiac events in certain diseases has been demonstrated. However, the association with new-onset atrial fibrillation (AF) after coronary artery bypass grafting (CABG) is still controversial. This study aimed to investigate the association between HRV and new-onset AF in patients undergoing CABG during a 6-month follow-up. Methods: This prospective study included 119 consecutive patients who underwent off-pump CABG. All patients were assessed using 24-hour Holter recordings 2 days before CABG and 1 week, 3 months, and 6 months postoperatively. HRV was analyzed, and AF was detected from its recordings. Main results: In patients undergoing CABG, NYHA III increased the AF rate 7 days postoperatively, and advanced age and diabetes were associated with AF 6 months postoperatively. A reduction in time-domain measurements before surgery was significantly associated with a higher risk of developing AF seven days postoperatively; no association between preoperative HRV and AF was found at six months. Reduced preoperative HRV (SDNN (standard deviation of all normal-to-normal intervals [) < 50 ms) was an independent predictor of AF at 3 (AUC = 0.65) and 6 months (AUC = 0.62) following surgery. Conclusion: A reduction in the time domain measurements before CABG was associated with a higher risk of new-onset AF at 7 days postoperatively but not at 6 months. An SDNN <50 ms was a weak independent predictor of a higher incidence of AF at 3 and 6 months post-surgery.

14.
J Asian Nat Prod Res ; : 1-11, 2023 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-37889019

RESUMO

Alkaloids are among the most important and best-known secondary metabolites as sources of new drugs from medicinal plants and marine organisms. A phytochemical investigation of the whole plant of Crinum asiaticum var. sinicum resulted in the isolation of seven alkaloids (1-7), including one new dimeric compound, bis-(-)-8-demethylmaritidine (1). Their structures were elucidated using NMR and HR-ESI-MS. The absolute configuration of new compound 1 was established by circular dichroism spectroscopy. All isolated compounds were evaluated for their inhibitory effects on acetylcholinesterase (AChE) activity in vitro. Among them, compound 1 exhibited the most potent AChE inhibition. Moreover, molecular docking and molecular dynamics simulations were carried out for the most active compound to investigate their binding interactions and dynamics behavior of the AChE protein-ligand complex. Therefore, compound 1 may be a potential candidate for effectively treating Alzheimer's disease.

15.
J Chem Theory Comput ; 19(20): 7187-7198, 2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37800673

RESUMO

It has become common to perform kinetic analysis using approximate Koopman operators that transform high-dimensional timeseries of observables into ranked dynamical modes. The key to the practical success of the approach is the identification of a set of observables that form a good basis on which to expand the slow relaxation modes. Good observables are, however, difficult to identify a priori and suboptimal choices can lead to significant underestimations of characteristic time scales. Leveraging the representation of slow dynamics in terms of Hidden Markov Models (HMM), we propose a simple and computationally efficient clustering procedure to infer surrogate observables that form a good basis for slow modes. We apply the approach to an analytically solvable model system as well as on three protein systems of different complexities. We consistently demonstrate that the inferred indicator functions can significantly improve the estimation of the leading eigenvalues of Koopman operators and correctly identify key states and transition time scales of stochastic systems, even when good observables are not known a priori.

16.
Acta Trop ; 248: 107034, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37793492

RESUMO

Rickettsia felis is an emerging flea-borne spotted fever pathogen that causes febrile illness in humans. In Vietnam, R. felis was detected in hospitalized patients, but there is no information on its presence in the Vietnamese community. This cross-sectional study aimed to determine the presence of R. felis in humans of the Central Highlands of Vietnam. A total of 158 blood and 213 serum samples were subjected to PCR and IFAT, respectively, to detect the presence of R. felis DNA and antibodies against R. felis. PCR assays detected R. felis DNA in four out of 158 blood samples, accounting for a prevalence of 2.53 % (95 % CI: 0.81 %-6.76 %). Phylogenetic analysis indicated the presence of R. felis and R. felis genotype RF2125 in the communities in the Central Highlands of Vietnam. The result of IFAT identified seven out of 213 serum samples (3.29 %, 95 % CI: 1.45 %-6.93 %) positive for antibodies against R. felis. This study was the first to demonstrate the presence of active R. felis infections in the communities in the Central Highlands of Vietnam utilizing both molecular and serological methods.


Assuntos
Infecções por Rickettsia , Rickettsia felis , Rickettsia , Sifonápteros , Animais , Humanos , Rickettsia felis/genética , Infecções por Rickettsia/microbiologia , Filogenia , Estudos Transversais , Vietnã/epidemiologia , Sifonápteros/microbiologia , DNA , Rickettsia/genética
17.
Thromb J ; 21(1): 108, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37864173

RESUMO

BACKGROUND: Hemophilia A (HEMA) is an X-linked bleeding disorder caused by reduced/absent coagulation factor VIII expression, as a result of pathogenic variants in the F8 gene. Preimplantation prevention of HEMA should ideally include direct pathogenic F8 variant detection, complemented by linkage analysis of flanking markers to identify the high-risk F8 allele. Linkage analysis is particularly indispensable when the pathogenic variant cannot be detected directly or identified. This study evaluated the suitability of a panel of F8 intragenic and extragenic short tandem repeat markers for standalone linkage-based preimplantation genetic testing for monogenic disorder (PGT-M) of the Inv22 pathogenic variant, an almost 600 kb paracentric inversion responsible for almost half of all severe HEMA globally, for which direct detection is challenging. METHODS: Thirteen markers spanning 1 Mb and encompassing both F8 and the Inv22 inversion interval were genotyped in 153 unrelated females of Viet Kinh ethnicity. RESULTS: All individuals were heterozygous for ≥ 1 marker, ~ 90% were heterozygous for ≥ 1 of the five F8 intragenic markers, and almost 98% were heterozygous for ≥ 1 upstream (telomeric) and ≥ 1 downstream (centromeric) markers. A prospective PGT-M couple at risk of transmitting F8 Inv22 were fully informative at four marker loci (2 intra-inversion, 1 centromeric, 1 telomeric) and partially informative at another five (2 intra-inversion, 3 centromeric), allowing robust phasing of low- and high-risk haplotypes. In vitro fertilization produced three embryos, all of which clearly inherited the low-risk maternal allele, enabling reliable unaffected diagnoses. A single embryo transfer produced a clinical pregnancy, which was confirmed as unaffected by amniocentesis and long-range PCR, and a healthy baby girl was delivered at term. CONCLUSION: Robust and reliable PGT-M of HEMA, including the common F8 Inv22 pathogenic variant, can be achieved with sufficient informative intragenic and flanking markers.

18.
ACS Appl Mater Interfaces ; 15(39): 45981-45996, 2023 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-37722029

RESUMO

The distribution of oxygen and aluminum vacancies across the hemispherical barrier oxide layer (BOL) of nanoporous anodic alumina (NAA) relies intrinsically on the electric field-driven flow of electrolytic species and the incorporation of electrolyte impurities during the growth of anodic oxide through anodization. This phenomenon provides new opportunities to engineer BOL's inherited ionic current rectification (ICR) fingerprints. NAA's characteristic ICR signals are associated with the space charge density gradient across BOL and electric field-induced ion migration through hopping from vacancy to vacancy. In this study, we engineer the intrinsic space charge density gradient of the BOL of NAA under a range of anodizing potentials in hard and mild anodization regimes. Real-time characterization of the ICR fingerprints of NAA during selective etching of the BOL makes it possible to unravel the distribution pattern of vacancies through rectification signals as a function of etching direction and time. Our analysis demonstrates that the space charge density gradient varies across the BOL of NAA, where the magnitude and distribution of the space charge density gradient are revealed to be critically determined by anodizing the electrolyte, regime, and potential. This study provides a comprehensive understanding of the engineering of ion transport behavior across blind-hole NAA membranes by tuning the distribution of defects across BOL through anodization conditions. This method has the potential to be harnessed for developing nanofluidic devices with tailored ionic rectification properties for energy generation and storage and sensing applications.

19.
MMWR Morb Mortal Wkly Rep ; 72(31): 838-843, 2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37535465

RESUMO

Fleaborne typhus (also known as murine typhus), a widely distributed vectorborne zoonosis caused by Rickettsia typhi, is a moderately severe, but infrequently fatal illness; among patients who receive doxycycline, the case-fatality rate is <1%. Fleaborne typhus is a mandated reportable condition in California. Reported fleaborne typhus cases in Los Angeles County have been increasing since 2010, with the highest number (171) reported during 2022. During June-October 2022, Los Angeles County Department of Public Health learned of three fleaborne typhus-associated deaths. This report describes the clinical presentation, illness course, and methods used to diagnose fleaborne typhus in these three cases. Severe fleaborne typhus manifestations among these cases included hemophagocytic lymphohistiocytosis, a rare immune hyperactivation syndrome that can occur in the infection setting; myocarditis; and septic shock with disseminated intravascular coagulation. Increased health care provider and public health awareness of the prevalence and severity of fleaborne typhus and of the importance of early doxycycline therapy is essential for prevention and treatment efforts.


Assuntos
Tifo Endêmico Transmitido por Pulgas , Tifo Epidêmico Transmitido por Piolhos , Camundongos , Humanos , Doxiciclina/uso terapêutico , Los Angeles/epidemiologia , Tifo Endêmico Transmitido por Pulgas/epidemiologia , Tifo Endêmico Transmitido por Pulgas/diagnóstico , Tifo Endêmico Transmitido por Pulgas/microbiologia , Rickettsia typhi , Animais
20.
Zootaxa ; 5284(2): 364-376, 2023 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-37518732

RESUMO

Two new genera of freshwater crabs (Potamidae) are recorded from northern Vietnam, Tortomon Huang, Wang & Shih, 2020, and Aiyunamon Pan, Ng & Sun, 2022. These genera had previously only been reported from southern China and eastern Myanmar. Each genus is represented by a new species. Tortomon distinctum n. sp. is markedly different from its two Chinese congeners in its proportionately wider carapace, more elongate third maxilliped, the carpus of the cheliped being armed only with a low tubercle, possessing relatively more slender and longer ambulatory legs, a gently curved male first gonopod and a more elongate male second gonopod. Aiyunamon vietnamicum n. sp. is distinct from its five congeners in its proportionately less convex dorsal surface of the carapace, relatively lower epigastric cristae, lower rugosities of the postorbital cristae, wider median lobe of the posterior margin of the epistome, relatively narrower male pleon, and a male first gonopod that has the terminal segment more distinctly curved with a wider concavity on the outer margin of the subterminal segment.


Assuntos
Braquiúros , Masculino , Animais , Vietnã , Florestas , Água Doce
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