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1.
Sci Rep ; 14(1): 13871, 2024 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-38879558

RESUMO

Enteric viral pathogens are associated with a significant burden of childhood morbidity and mortality. We investigated the relationship between viral pathogens and child growth among under-5 children. We analyzed data from 5572/22,567 children enrolled in the Global Enteric Multicenter Study across seven study sites (2007-2011). Multiple linear regression was used to examine the association between the viral pathogens and changes of length/height-for-age (HAZ), weight-for-age (WAZ), and weight-for-length/height (WHZ) z-scores, stratified by diarrheal symptoms and adjusted for potential covariates. Rotavirus (18.51%) and norovirus (7.33%) were the most prevalent enteric viral pathogens among symptomatic and asymptomatic under-5 children, respectively. Infection with individual enteric viral pathogens hurts child growth in asymptomatic children. However, the relationship with HAZ was less clear and statistically non-significant. On the other hand, the combined viral pathogens demonstrated a strong negative influence on child growth [WAZ: ß coef.: - 0.10 (95%, CI - 0.15, - 0.05); P < 0.001 and WHZ: ß: - 0.12 (95% CI - 0.17, - 0.07); P < 0.001] among asymptomatic children. Infection with any viral pathogen was associated with growth shortfalls [HAZ: ß: - 0.05 (95% CI - 0.09, 0.00); P = 0.03 and WAZ: ß: - 0.11 (95% CI - 0.16, - 0.07); P < 0.001 and WHZ: ß: - 0.13 (95% CI - 0.18, - 0.09); P < 0.001], though the relationship with HAZ was less evident and became statistically non-significant in older children. Notably, among symptomatic children with moderate-to-severe diarrhea, individual enteric viral pathogens, as well as the combined effects of these pathogens [WHZ: ß: 0.07; (95% CI 0.01, 0.14); P = 0.03] and the presence of any virus [HAZ: ß: 0.09 (95% CI 0.05, 0.13) & WAZ: ß: 0.08 (95% CI 0.03, 0.12); P < 0.001], exhibited positive effects on child growth. While previous studies hypothesized that several viral pathogens had a conflicting controversial role in child growth, we find clear indications that enteric viral pathogens are associated with growth shortfalls, specifically among asymptomatic children. These findings highlight the need for preventive strategies targeting children with enteric viral pathogens, which could address the consequences of growth faltering.


Assuntos
Rotavirus , Humanos , Lactente , Pré-Escolar , Feminino , Masculino , África Subsaariana/epidemiologia , Ásia/epidemiologia , Diarreia/virologia , Diarreia/epidemiologia , Desenvolvimento Infantil , Norovirus , Infecções por Rotavirus/epidemiologia , Recém-Nascido , Ásia Meridional
2.
bioRxiv ; 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38854067

RESUMO

How cells establish the interphase genome organization after mitosis is incompletely understood. Using quantitative and super-resolution microscopy, we show that the transition from a Condensin to a Cohesin-based genome organization occurs dynamically over two hours. While a significant fraction of Condensins remains chromatin-bound until early G1, Cohesin-STAG1 and its boundary factor CTCF are rapidly imported into daughter nuclei in telophase, immediately bind chromosomes as individual complexes and are sufficient to build the first interphase TAD structures. By contrast, the more abundant Cohesin-STAG2 accumulates on chromosomes only gradually later in G1, is responsible for compaction inside TAD structures and forms paired complexes upon completed nuclear import. Our quantitative time-resolved mapping of mitotic and interphase loop extruders in single cells reveals that the nested loop architecture formed by sequential action of two Condensins in mitosis is seamlessly replaced by a less compact, but conceptually similar hierarchically nested loop architecture driven by sequential action of two Cohesins.

3.
J Agric Food Chem ; 72(25): 14274-14283, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38867465

RESUMO

ß-Alanine, a valuable ß-type amino acid, is experiencing increased demand due to its multifaceted applications in food flavoring, nutritional supplements, pharmaceuticals, and the chemical industry. Nevertheless, the sustainable biosynthesis of ß-alanine currently faces challenges due to the scarcity of robust strains, attributed to the complexities of modulating multiple genes and the inherent physiological constraints. Here, systems metabolic engineering was implemented in Escherichia coli to overcome these limitations. First, an efficient l-aspartate-α-decarboxylase (ADC) was recruited for ß-alanine biosynthesis. To conserve phosphoenolpyruvate flux, we subsequently modified the endogenous glucose assimilation system by inactivating the phosphotransferase system (PTS) and introducing an alternative non-PTS system, which increased ß-alanine production to 1.70 g/L. The supply of key precursors, oxaloacetate and l-aspartate, was synergistically improved through comprehensive modulation, including strengthening main flux and blocking bypass metabolism, which significantly increased the ß-alanine titer to 3.43 g/L. Next, the expression of ADC was optimized by promoter and untranslated region (UTR) engineering. Further transport engineering, which involved disrupting ß-alanine importer CycA and heterologously expressing ß-alanine exporter NCgI0580, improved ß-alanine production to 8.48 g/L. Additionally, corn steep liquor was used to develop a cost-effective medium. The final strain produced 74.03 g/L ß-alanine with a yield of 0.57 mol/mol glucose during fed-batch fermentation.


Assuntos
Escherichia coli , Fermentação , Glucose , Engenharia Metabólica , beta-Alanina , beta-Alanina/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Glucose/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Glutamato Descarboxilase/genética , Glutamato Descarboxilase/metabolismo
4.
J Agric Food Chem ; 72(25): 14264-14273, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38860833

RESUMO

Ergothioneine (EGT) is a naturally occurring derivative of histidine with diverse applications in the medicine, cosmetic, and food industries. Nevertheless, its sustainable biosynthesis faces hurdles due to the limited biosynthetic pathways, complex metabolic network of precursors, and high cost associated with fermentation. Herein, efforts were made to address these limitations first by reconstructing a novel EGT biosynthetic pathway from Methylobacterium aquaticum in Escherichia coli and optimizing it through plasmid copy number. Subsequently, the supply of precursor amino acids was promoted by engineering the global regulator, recruiting mutant resistant to feedback inhibition, and blocking competitive pathways. These metabolic modifications resulted in a significant improvement in EGT production, increasing from 35 to 130 mg/L, representing a remarkable increase of 271.4%. Furthermore, an economical medium was developed by replacing yeast extract with corn steep liquor, a byproduct of wet milling of corn. Finally, the production of EGT reached 595 mg/L with a productivity of 8.2 mg/L/h by exploiting fed-batch fermentation in a 10 L bioreactor. This study paves the way for exploring and modulating a de novo biosynthetic pathway for efficient and low-cost fermentative production of EGT.


Assuntos
Vias Biossintéticas , Ergotioneína , Escherichia coli , Fermentação , Engenharia Metabólica , Ergotioneína/biossíntese , Ergotioneína/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Reatores Biológicos
5.
Mymensingh Med J ; 33(3): 649-655, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38944702

RESUMO

Antibiotics' usefulness is threatened by multi-drugs resistance in harmful microorganisms because of abuse and regulatory problems. Emerging microbes, resistance mechanisms and antimicrobial drugs all require extensive investigation. Evaluation of the in vitro antibacterial activity of Methanolic extracts isolated from Black pepper seeds (Piper nigrum L.) against two infection causing pathogens, Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa. From July 2022 and June 2023, this experimental study was conducted at the Mymensingh Medical College's Department of Pharmacology and Therapeutics in conjunction with the Department of Microbiology. The solvents Methanol and 10.0% Di-Methyl Sulfoxide (DMSO) were used to make the extract. Using the disc diffusion and broth dilution methods, the antibacterial activity of methanolic extract of black pepper seeds (MBPE) was evaluated at various doses. Using the broth dilution procedure, the conventional antibiotic Ciprofloxacin was utilized, and the outcome was contrasted with that of Methanol extracts. Methanolic extract of black pepper seeds (MBPE) at seven distinct concentrations (100, 80, 60, 40, 20, 10 and 5mg/ml) were utilized, then later in chosen concentrations as needed to confirm the extracts' more precise margin of antimicrobial sensitivity. At 80mg/ml and above doses of the MBPE, it had an inhibitory impact against the aforementioned microorganisms. For Staphylococcus aureus and Pseudomonas aeruginosa the MIC were 60 and 70mg/ml in MBPE respectively. As of the MIC of Ciprofloxacin was 1µg/ml against Staphylococcus aureus and 1.5µg/ml for Pseudomonas aeruginosa. In comparison to MICs of MBPE for the test organisms, the MIC of Ciprofloxacin was the lowest. This study clearly shows that Staphylococcus aureus and Pseudomonas aeruginosa are sensitive to the methanolic extract of black pepper seeds' antibacterial properties.


Assuntos
Antibacterianos , Metanol , Testes de Sensibilidade Microbiana , Piper nigrum , Extratos Vegetais , Pseudomonas aeruginosa , Sementes , Staphylococcus aureus , Piper nigrum/química , Pseudomonas aeruginosa/efeitos dos fármacos , Extratos Vegetais/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/farmacologia
6.
Mymensingh Med J ; 33(3): 690-695, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38944708

RESUMO

Burns are very common and important injuries associated with epilepsy. Epileptics are afflicted with burns when they come in contact with fire or other burning agents while seizing, due to loss of consciousness. The aim of the study was to identify the causes of burn, pattern and characteristics of burn in patients with epilepsy, duration of hospital stay and pattern of treatment in these patients. This prospective observational study was conducted in the Department of Burn and Plastic Surgery, Mymensingh Medical College Hospital, Bangladesh from January 2022 to December 2023. Epileptics were found in 0.84% (n=19) of the total admission (2274) in Burn unit. Majority of the patients were females (84.2%) and the mean age was (31.42±1.32) years. Maximum patients were housewives (78.9%). Among 19 cases, 11 cases (57.89%) had history of irregularly taking antiepileptic drugs and 8 cases (42.11%) had no history of treatment for epilepsy. Two cases (10.53%) had history of previous burn injury. Flame burn was the major etiology (89.5%). Mean total burn surface area (TBSA) was (6.94±4.12%). Most patients had full thickness burns (63.2%). Regarding distribution of burn, maximum involvement was in upper limb i.e. 68.21% cases. Surgical treatment was needed in the majority of the patients (68.5%). Mean hospital stay of these patients was (5.36±2.26) weeks. Epilepsy patients whose seizures are inadequately controlled are at increased risks of injury, especially burn. For prevention of burn, epilepsy should be treated properly.


Assuntos
Queimaduras , Epilepsia , Humanos , Feminino , Bangladesh/epidemiologia , Masculino , Adulto , Queimaduras/epidemiologia , Queimaduras/terapia , Queimaduras/complicações , Epilepsia/epidemiologia , Epilepsia/etiologia , Estudos Prospectivos , Tempo de Internação/estatística & dados numéricos , Centros de Atenção Terciária/estatística & dados numéricos , Adulto Jovem , Pessoa de Meia-Idade , Adolescente
7.
Mymensingh Med J ; 33(3): 724-730, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38944713

RESUMO

Among patients with chronic kidney disease stage-5 who are treated with dialysis, the urea clearance during hemodialysis is a determinant of the mortality. Decreased serum albumin, serum calcium but increased phosphorus is associated with reduction of URR and mortality in these patients. This study was to compare two groups Urea Reduction Ratio (URR) and different type of biochemical parameters. URR was aimed to target according to Kidney Disease Outcomes Quality Initiative (KDOQI) guideline. This study was an observational study was carried out in the department of Nephrology. Serum Albumin, serum calcium, phosphate, hemoglobin and pre dialysis urea, post dialysis urea were measured from blood sample. URR was calculated by = (1- postdialysis urea/predialysis urea) × 100. Among the patients who under went hemodialysis, 17.31% patients URR was more than 65.0% and Mean±SD of URR was 67.21±1.9%. On the other hand, 82.68% patients URR was less than 65.0% and Mean±SD of URR was 57.4±5.2%. Most of the Biochemical parameters in this study were significantly different between two groups. Where as, there was no significant difference in Age, Sex, Body Mass Index (BMI). The URR is an accurate indicator, can help determination of adequate dialysis. This study aimed to find out the mean value of the urea reduction ratio and the association of biochemical parameters among End Stage Renal Disease (ESRD) patients on maintenance hemodialysis.


Assuntos
Diálise Renal , Ureia , Humanos , Diálise Renal/métodos , Ureia/sangue , Feminino , Masculino , Bangladesh , Pessoa de Meia-Idade , Adulto , Falência Renal Crônica/terapia , Falência Renal Crônica/sangue , Idoso
8.
Mymensingh Med J ; 33(3): 750-757, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38944717

RESUMO

The presence of bright resonance of more than 1 mm or more cusps of the aortic valve, mitral valve or mitral annulus is termed as cardiac valve calcification. If an intense echo producing structure located at the junction of the atrioventricular groove and posterior mitral valve leaflet on Echocardiography that is Mitral annular calcification (MAC). This study was conducted to observe the association of MAC with clinical and echocardiographic findings of ischemic heart disease (IHD) and the role of trans-thoracic echocardiography to detect MAC which is a marker IHD. In this prospective, observational, case-control study, total of 100 IHD patients, 50 patients with MAC were assigned as case group and 50 patients without MAC were control group after fulfilling inclusion criteria. All the detailed history, clinical examination and relevant investigation reports of each patient were recorded in pre designed data collection sheet. MAC was detected with transthorasic echocardiography. Analysis was done to observe the association and correlation of MAC with clinical findings of IHD. Mean age of the case control was 55.16±10.73 years and control was 49.80±8.84 years. MAC was noted highest about 56.0% in between age 45 to 60 years. Eighty two percent (82.0%) of cases and 84.0% of controls were male, 18.0% of cases and 16.0% of controls were female. BMI among the MAC group 2.0% were underweight, 72.0% normal, 24.0% over weight and 2.0% were obese and among non MAC controls group 10.0% were underweight, 68.0% normal, 20.0% over weight and 2.0% were obese. Clinically among cases 14(28.0%) had Stable angina, 8(16.0%) had UA, 3(6.0%) had Non STEMI, 2(4.0%) had AMI, 2(4.0%) had Recent myocardial infarction and 21(42.0%) had OMI. Diabetes mellitus was significantly higher in the case groups (p=0.006). Significant p-value was noted in hyper-triyglyceridemia and low HDL in case group than control. Echocardiographic studies showed 52.0% of cases and 32.0% of controls had regional wall motion abnormality (RWMA). Transthorasic echocardiographically detected MAC is an independent predictor of Ischemic heart disease. The low cost, portable and radiation free nature of the ultrasound approach make MAC an attractive parameter in the ongoing search for IHD.


Assuntos
Calcinose , Ecocardiografia , Valva Mitral , Isquemia Miocárdica , Centros de Atenção Terciária , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Isquemia Miocárdica/diagnóstico por imagem , Calcinose/diagnóstico por imagem , Estudos de Casos e Controles , Ecocardiografia/métodos , Valva Mitral/diagnóstico por imagem , Valva Mitral/patologia , Estudos Prospectivos , Doenças das Valvas Cardíacas/diagnóstico por imagem , Doenças das Valvas Cardíacas/complicações , Idoso , Adulto
9.
Mymensingh Med J ; 33(3): 805-809, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38944725

RESUMO

Stroke is one of the most common neurological disorder and third most common cause of death in the world. Low vitamin D concentrations have been shown to predict risk of cardiovascular disease and all-cause of mortality. The aim of this study was to estimate serum vitamin D level in acute ischemic stroke patients. This comparative cross-sectional type of study was conducted in the Department of Neurology and Department of Medicine at Mymensingh Medical College and Hospital, Bangladesh from November 2017 to June 2019 with a total number of 100 study subjects. Total fifty patients with acute ischemic stroke were enrolled in Group A and another fifty age and sex matched volunteer subjects were enrolled in Group B with no prior history of stroke or transient ischemic attacks. Serum vitamin D levels, fasting plasma glucose and lipid profile were assessed in both groups and compared with each other. P value <0.05 was considered as significant in the study. Mean fasting blood sugar, serum fasting total cholesterol (TC), serum fasting triglycerides, serum fasting Low density lipoprotein (LDL) were significantly higher in Group A than Group B (p<0.05). Serum vitamin D level in Group A was 25.28±8.47ng/ml and in Group B was 30.90±5.80, (p=0.001). Insufficient vitamin D level was found in 52.0% of ischemic stroke patients and in 30% of healthy controls (p=0.0002). Vitamin D deficiency was found in 20.0% ischemic stroke patients and 10.0% in healthy controls. This study demonstrates a positive association between low serum vitamin D level and acute ischemic stroke. Further studies are required to determine whether vitamin D supplementation could improve functional outcome in patients with ischemic stroke.


Assuntos
AVC Isquêmico , Deficiência de Vitamina D , Vitamina D , Humanos , Masculino , Feminino , Vitamina D/sangue , AVC Isquêmico/sangue , AVC Isquêmico/epidemiologia , Estudos Transversais , Pessoa de Meia-Idade , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/epidemiologia , Bangladesh/epidemiologia , Idoso , Adulto , Estudos de Casos e Controles , Glicemia/análise
10.
Mymensingh Med J ; 33(3): 932-935, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38944743

RESUMO

Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome is a rare congenital disorder that affects the female reproductive system and is characterized by an underdeveloped or absent uterus and vagina. A 17-year-old unmarried female was admitted into the Department of Endocrinology, Mymensingh Medical College Hospital, Bangladesh in November 2023 for evaluation of primary amenorrhea and poorly controlled diabetes mellitus. She was the 5th issue of non-consanguineous marriage delivered at term by normal vaginal delivery. Her growth pattern and developmental milestones were normal. She had no history of galactorrhea, chronic or cyclic pelvic pain, thyroid dysfunction, excessive exercise, psychiatric illness, or drug abuse. There was no history of such type of illness in her family. She was diagnosed with diabetes mellitus two years back without classic symptoms, and at that time, her blood glucose was 22 mmol/L. She was prescribed metformin and gliclazide. She had no history of hypoglycemia, hyperglycemic crises, or hospital admission. On examination, her body build and nutritional status were normal. Anemia, jaundice, edema, dehydration, lymphadenopathy, acne, hirsutism, acanthosis nigricans, abdominal striae and vitiligo were absent. Her blood pressure was 110/70 without the postural drop, thyroid gland was not enlarged, anthropometric measurements were normal and BMI was 18.4 kg/m2. Her tanner stage was P5 & B4. Genital examination revealed normal female external genitalia, and a blind vaginal pouch was found. Other systemic examinations revealed no abnormality. On laboratory reports, her blood glucose was uncontrolled (HbA1c-10.2%) with glycosuria. Thyroid function test and gonadal hormones were normal. Ultrasonogram of the abdomen revealed uterus, cervix, and upper part of the vagina are absent, and an ectopic left kidney.


Assuntos
Transtornos 46, XX do Desenvolvimento Sexual , Amenorreia , Anormalidades Congênitas , Ductos Paramesonéfricos , Humanos , Feminino , Adolescente , Amenorreia/etiologia , Transtornos 46, XX do Desenvolvimento Sexual/complicações , Transtornos 46, XX do Desenvolvimento Sexual/diagnóstico , Anormalidades Congênitas/diagnóstico , Ductos Paramesonéfricos/anormalidades , Diabetes Mellitus
11.
Mar Pollut Bull ; 204: 116544, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38824706

RESUMO

Plastic particles have emerged as a growing threat to both ecosystems and human well-being, as they are being ingested and accumulate at different trophic levels. However, microplastic and mesoplastic contamination and its risk to coastal and marine water fish have not been well studied, particularly in the northern Bay of Bengal. In this study, the presence of small-scale plastic particles (micro- and meso-sized) in the gastrointestinal tract (GIT) and muscles of six edible fish species from the northern Bay of Bengal Coast were identified and analyzed. The overall range of microplastics was 1.74 ± 0.23-3.79 ± 2.03items/g in muscle and 0.54 ± 0.22-5.96 ± 3.16 items/g in the GIT, with 16.38 ± 8.08-31.88 ± 12.09 items/individual. No mesoplastics were found in muscle tissue, but they were present in the GIT at concentrations ranging from 0.33 ± 0.27 to 0.03 ± 0.02 items/g and from 0.51 ± 0.05to 1.38 ± 1.01 items/individual. Lepturacanthus savala accumulated the most microplastics in muscle, and Harpadon nehereus had the least. In addition, the highest levels of mesoplastics were detected in the GIT of Polynemus paradiseus and the lowest was detected in the GIT of Lutjenus sanguineus. Omnivorous fish showed higher plastic concentrations than carnivorous fish, which was linked to dietary habits, feeding strategies and digestive processes. Plastic material predominantly accumulated in the GIT rather than in the muscle. The majority of ingested plastic particles were fibres (95.18 %), were violet in color (34 %), and were < 0.5 mm in size (87 %). The dominant microplastic polymers included 38 % PE, 15 % PP, 33 % PU, and 14 % CES. In contrast, the prevalent mesoplastic polymers comprised 45 % PE, 19 % PP, 13 % PS, 16 % PA, and 7 % PET. Subsequently, a hazard analysis using the polymer hazard index (PHI) revealed that plastic contamination was of distinct hazard categories for different polymer types, ranging from grade I (<1) to grade IV (100-1000). The assessment of the contamination factor (1 < CF < 3) and pollution load index (PLI > 1) indicated moderate contamination of fish by the ingestion of plastic debris. This study provides the foremost evidence for the presence of mesoplastics and microplastics in coastal and marine fish in the study region, paving the way for future investigations and policy implementation.


Assuntos
Baías , Monitoramento Ambiental , Peixes , Microplásticos , Plásticos , Poluentes Químicos da Água , Animais , Microplásticos/análise , Poluentes Químicos da Água/análise , Medição de Risco , Baías/química , Plásticos/análise , Índia , Ecossistema
12.
RSC Adv ; 14(21): 15085-15094, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38720970

RESUMO

Water contamination due to organic pollutants is a challenging issue around the globe, and several attempts have been made to deal with this issue. Out of which, the semiconductor-based photocatalytic process had gained much attention and proved to be an efficient, easy, and economical process for the removal of organic dyes from aqueous solutions. For this purpose, the iron oxide-zirconium dioxide nanocomposite (Fe2O3-ZrO2 NC) was prepared via a simple mechanochemical process using a mortar and pestle, followed by a calcination process at 300, 600, and 900 °C. Different physicochemical analyses were carried out in order to investigate the successful synthesis of Fe2O3-ZrO2 NC and the effect of temperature on the crystallinity, surface area, pore size, phase composition, sample morphology, and particle/crystallite size. The Fe2O3-ZrO2 NCs were subjected to a photocatalytic test under solar light irradiation against fluorescein dye in an aqueous medium, and the photocatalytic performance was examined under the influence of calcination temperatures, pH, catalyst dose, and initial concentration. The stability of the Fe2O3-ZrO2 NCs was also checked by recycling them for five reuse cycles.

13.
ACS Nano ; 18(19): 12377-12385, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38701373

RESUMO

Two-dimensional electronic materials are a promising candidate for beyond-silicon electronics due to their favorable size scaling of electronic performance. However, a major challenge is the heterogeneous integration of 2D materials with CMOS processes while maintaining their excellent properties. In particular, there is a knowledge gap in how thin film deposition and processes interact with 2D materials to alter their strain and doping, both of which have a drastic impact on device properties. In this study, we demonstrate how to utilize process-induced strain, a common technique extensively applied in the semiconductor industry, to enhance the carrier mobility in 2D material transistors. We systematically varied the tensile strain in monolayer MoS2 transistors by iteratively depositing thin layers of high-stress MgOx stressor. At each thickness, we combined Raman spectroscopy and transport measurements to unravel and correlate the changes in strain and doping within each transistor with their performance. The transistors displayed uniform strain distributions across their channels for tensile strains of up to 0.48 ± 0.05%, at 150 nm of stressor thickness. At higher thicknesses, mechanical instability occurred, leading to nonuniform strains. The transport characteristics systematically varied with strain, with enhancement in electron mobility at a rate of 130 ± 40% per % strain and enhancement of the channel saturation current density of 52 ± 20%. This work showcases how established CMOS technologies can be leveraged to tailor the transport in 2D transistors, accelerating the integration of 2D electronics into a future computing infrastructure.

14.
Heliyon ; 10(10): e31138, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38778989

RESUMO

In perovskite solar cells (PSCs), the charge carrier recombination obstacles mainly occur at the ETL/perovskite and HTL/perovskite interfaces, which play a decisive role in the solar cell performance. Therefore, this study aims to enhance the flexible PSC (FPSC) efficiency by adding the newly designed CBz-PAI-interlayer (simply CBz-PAI-IL) at the perovskite/HTL interface. In addition, substantial work has been carried out on five different HTLs (Se/Te-Cu2O, CuGaO2, V2O5, and CuSCN, including conventional Spiro-OMeTAD as a reference HTL with and without CBz-PAI-IL), using drift-diffusion simulation to find suitable FPSC design to attain the maximum PCE. Interestingly, PET/ITO/AZO/ZnO NWs/FACsPbBrI3/CBz-PAI/Se/Te-Cu2O/Au device architecture demonstrates the highest achievable power conversion efficiency (PCE) of 27.9 %. The findings of this study confirmed that the reference device (without IL) displays a large valence band edge (VBE)/highest occupied molecular orbital (HOMO) energy level misalignment compared to the modified interface device (with CBz-PAI-IL that reduces VBE/HOMO level mismatch) that eases the hole transport, simultaneously, it reduces the charge carrier recombinations at the interface, resulting in diminished Voc losses in the device. Furthermore, the influence of perovskite absorber thickness and defect density, parasitic resistances, and working temperature are systematically examined to govern the superior FPSC efficiency and concurrently understand the device physics.

15.
Sci Rep ; 14(1): 12460, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38816518

RESUMO

The Schockley-Quisser (SQ) limit of 28.64% is distant from the Sb2S3 solar cells' record power conversion efficiency (PCE), which is 8.00%. Such poor efficiency is mostly owing to substantial interface-induced recombination losses caused by defects at the interfaces and misaligned energy levels. The endeavor of this study is to investigate an efficient Sb2S3 solar cell structure via accurate analytical modeling. The proposed model considers different recombination mechanisms such as non-radiative recombination, Sb2S3/CdS interface recombination, Auger, SRH, tunneling-enhanced recombination, and their combined impact on solar cell performance. This model is verified against experimental work (Glass/ITO/CdS/Sb2S3/Au) where a good coincidence is achieved. Several parameters effects such as thickness, doping, electronic affinity, and bandgap are scrutinized. The effect of both bulk traps located in CdS and Sb2S3 on the electrical outputs of the solar cell is analyzed thoroughly. Besides, a deep insight into the effect of interfacial traps on solar cell figures of merits is gained through shedding light into their relation with carriers' minority lifetime, diffusion length, and surface recombination velocity. Our research findings illuminate that the primary contributors to Sb2S3 degradation are interfacial traps and series resistance. Furthermore, achieving optimal band alignment by fine-tuning the electron affinity of CdS to create a Spike-like conformation is crucial for enhancing the immunity of the device versus the interfacial traps. In our study, the optimized solar cell configuration (Glass/ITO/CdS/Sb2S3/Au) demonstrates remarkable performance, including a high short-circuit current (JSC) of 47.9 mA/cm2, an open-circuit voltage (VOC) of 1.16 V, a fill factor (FF) of 54%, and a notable improvement in conversion efficiency by approximately 30% compared to conventional solar cells. Beyond its superior performance, the optimized Sb2S3 solar cell also exhibits enhanced reliability in mitigating interfacial traps at the CdS/Sb2S3 junction. This improved reliability can be attributed to our precise control of band alignment and the fine-tuning of influencing parameters.

16.
Mar Pollut Bull ; 203: 116429, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38705003

RESUMO

This study aims to assess seasonal and spatial variations, contamination status, ecological risks, and metal sources (Ni, Pb, Cr, Cu, Mn, and Zn) in human-afforested mangrove sediments in a deltaic region. Five sampling locations were sampled during dry and wet seasons. Heavy metal concentrations followed the order: Mn > Zn > Ni > Cr > Cu > Pb. Metal loads, except Cu and Pb, were higher during the dry season, aligning with national and international recommendations. Sediment quality guidelines, contamination factor, geoaccumulation index, enrichment factors, and pollution load index indicated uncontaminated sediment in both seasons. Potential ecological risk assessment showed low risk conditions in all sites. However, modified hazard quotient indicated moderate pollution risk from all metals except Pb. Analysis suggests anthropogenic sources, particularly evident near shipbreaking yards in Sitakunda. While initially uncontaminated, ongoing metal influx poses a potential risk to mangrove ecosystems.


Assuntos
Monitoramento Ambiental , Sedimentos Geológicos , Metais Pesados , Poluentes Químicos da Água , Áreas Alagadas , Metais Pesados/análise , Sedimentos Geológicos/química , Medição de Risco , Poluentes Químicos da Água/análise , Estações do Ano
17.
PLoS One ; 19(5): e0299386, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38753678

RESUMO

Malaria is the most common cause of death among the parasitic diseases. Malaria continues to pose a growing threat to the public health and economic growth of nations in the tropical and subtropical parts of the world. This study aims to address this challenge by developing a predictive model for malaria outbreaks in each district of The Gambia, leveraging historical meteorological data. To achieve this objective, we employ and compare the performance of eight machine learning algorithms, including C5.0 decision trees, artificial neural networks, k-nearest neighbors, support vector machines with linear and radial kernels, logistic regression, extreme gradient boosting, and random forests. The models are evaluated using 10-fold cross-validation during the training phase, repeated five times to ensure robust validation. Our findings reveal that extreme gradient boosting and decision trees exhibit the highest prediction accuracy on the testing set, achieving 93.3% accuracy, followed closely by random forests with 91.5% accuracy. In contrast, the support vector machine with a linear kernel performs less favorably, showing a prediction accuracy of 84.8% and underperforming in specificity analysis. Notably, the integration of both climatic and non-climatic features proves to be a crucial factor in accurately predicting malaria outbreaks in The Gambia.


Assuntos
Surtos de Doenças , Aprendizado de Máquina , Malária , Máquina de Vetores de Suporte , Gâmbia/epidemiologia , Humanos , Malária/epidemiologia , Redes Neurais de Computação , Algoritmos
18.
Cancer Lett ; 592: 216919, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38704133

RESUMO

Efforts to develop targetable molecular bases for drug resistance for pancreatic ductal adenocarcinoma (PDAC) have been equivocally successful. Using RNA-seq and ingenuity pathway analysis we identified that the superpathway of cholesterol biosynthesis is upregulated in gemcitabine resistant (gemR) tumors using a unique PDAC PDX model with resistance to gemcitabine acquired in vivo. Analysis of additional in vitro and in vivo gemR PDAC models showed that HMG-CoA synthase 2 (HMGCS2), an enzyme involved in cholesterol biosynthesis and rate limiting in ketogenesis, is overexpressed in these models. Mechanistic data demonstrate the novel findings that HMGCS2 contributes to gemR and confers metastatic properties in PDAC models, and that HMGCS2 is BRD4 dependent. Further, BET inhibitor JQ1 decreases levels of HMGCS2, sensitizes PDAC cells to gemcitabine, and a combination of gemcitabine and JQ1 induced regressions of gemR tumors in vivo. Our data suggest that decreasing HMGCS2 may reverse gemR, and that HMGCS2 represents a useful therapeutic target for treating gemcitabine resistant PDAC.


Assuntos
Azepinas , Carcinoma Ductal Pancreático , Desoxicitidina , Resistencia a Medicamentos Antineoplásicos , Gencitabina , Hidroximetilglutaril-CoA Sintase , Neoplasias Pancreáticas , Triazóis , Ensaios Antitumorais Modelo de Xenoenxerto , Animais , Humanos , Camundongos , Antimetabólitos Antineoplásicos/farmacologia , Azepinas/farmacologia , Proteínas que Contêm Bromodomínio , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/patologia , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Hidroximetilglutaril-CoA Sintase/metabolismo , Hidroximetilglutaril-CoA Sintase/genética , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/antagonistas & inibidores , Triazóis/farmacologia , Feminino , Camundongos SCID
19.
Mymensingh Med J ; 33(2): 350-355, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38557509

RESUMO

Evaluation of the in vitro antibacterial activity of Methanolic extracts isolated from Black pepper seeds (Piper nigrum L.) against two infection causing pathogens, Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. Between July 2022 and June 2023, this experimental study was conducted at the Mymensingh Medical College's Department of Pharmacology and Therapeutics in conjunction with the Department of Microbiology. Using the disc diffusion and broth dilution methods, the antibacterial activity of methanolic extract of black pepper seeds (MBPE) was evaluated at various doses. The solvents Methanol and 10.0% Di Methyl Sulfoxide (DMSO) were used to make the extract. Using the broth dilution procedure, the conventional antibiotic Ciprofloxacin was utilized and the outcome was contrasted with that of Methanol extracts. Methanolic extract of black pepper seeds (MBPE) at seven distinct concentrations (100, 80, 60, 40, 20, 10 and 5 mg/ml) were utilized, then later in chosen concentrations as needed to confirm the extracts' more precise margin of antimicrobial sensitivity. At 80 mg/ml and above doses of the MBPE, it had an inhibitory impact against the aforementioned microorganisms. For Staphylococcus aureus and Escherichia coli the MIC were 60 and 75 mg/ml in MBPE respectively. As of the MIC of Ciprofloxacin was 1µg/ml against Staphylococcus aureus and Escherichia coli. In comparison to MICs of MBPE for the test organisms, the MIC of Ciprofloxacin was the lowest. This study clearly shows that Staphylococcus aureus and Escherichia coli are sensitive to the methanolic extract of black pepper seeds' antibacterial properties.


Assuntos
Piper nigrum , Staphylococcus aureus , Humanos , Metanol , Extratos Vegetais/farmacologia , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Ciprofloxacina , Sementes , Escherichia coli
20.
Mymensingh Med J ; 33(2): 365-372, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38557512

RESUMO

Hypertension is a common disorder of major clinical, public health and economic importance. It affects men and women of all ages, and the prevalence is increasing in most countries. Maintenance of blood pressure below 140/90 mm of Hg is recommended by most of the guideline available around the world. Various classes of drugs are being used in the treatment of hypertension. Losartan potassium and amlodipine are two different antihypertensive agents belonging to two different groups used commonly around the world in treating essential hypertension. Losartan potassium is non-peptide Angiotensin-II receptor antagonist. Amlodipine which is the third generation dihydropyridine group of calcium channel blocker. The aim of the study was to compare the efficacy and safety of amlodipine and losartan for the treatment of essential hypertensive patients (18-75 years). A non-randomized comparative observational study was conducted in the Department of Pharmacology and Therapeutics in collaboration with Department of Medicine, Sylhet, MAG Osmani Medical College, Sylhet, Bangladesh from July 2021 to June 2022. In this study non-randomization was in two groups. Group A received amlodipine 5mg daily at morning and Group B received losartan potassium 50mg daily at night. The study parameters were systolic blood pressure (SBP), diastolic blood pressure (DBP), ankle oedema, serum K+ level. The result of treatment outcome was compared between two groups. After treatment the reduction of SBP was 5.19±2.93mm of Hg versus 3.27±1.34mm of Hg (p<0.001); reduction of DBP was 1.7±0.70 mm of Hg versus 0.68 mm of Hg (p<0.001) and serum K+ level 4.22±0.27mmol/L versus 4.21±0.16mmol/L (p<0.719) in amlodipine and losartan group respectively. Amlodipine is more effective than losartan potassium in respect to treatment of essential hypertension. Regarding adverse events losartan potassium causes angioedema, hyperkalemia, headache, dizziness etc. The study concluded that amlodipine is superior to losartan potassium in treating essential hypertension.


Assuntos
Hipertensão , Mercúrio , Masculino , Humanos , Feminino , Losartan/uso terapêutico , Losartan/farmacologia , Anlodipino/uso terapêutico , Anlodipino/farmacologia , Bangladesh , Centros de Atenção Terciária , Anti-Hipertensivos/uso terapêutico , Hipertensão/tratamento farmacológico , Hipertensão Essencial/tratamento farmacológico , Hipertensão Essencial/induzido quimicamente , Pressão Sanguínea , Resultado do Tratamento , Mercúrio/farmacologia , Mercúrio/uso terapêutico , Método Duplo-Cego
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