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1.
Org Lett ; 2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-38985500

RESUMEN

We developed a new transient directing group, N-(2-benzoyl-4-chlorophenyl)-1,1,1-trifluoromethanesulfonamide, which can facilitate the γ-monoarylation of free amines containing symmetric γ-C-H bonds. A variety of amines containing symmetric and identical γ-C(sp3)-H and γ-C(sp2)-H reacted with a diverse range of aryl and heteroaryl iodides to provide γ-monoarylated products exclusively.

3.
Clin Transl Oncol ; 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38958900

RESUMEN

BACKGROUND: The correlation between breast cancer and hepatitis B virus (HBV) remains inconclusive. This study aims to explore the serological status of HBV infection and past infection in different age groups of female breast cancer patients, patients with benign breast diseases, and individuals undergoing routine physical examinations. METHODS: Serum data on HBV serological markers were collected and analyzed from 6072 female breast cancer patients first diagnosed from September 2012 to July 2020 at the First Affiliated Hospital of Chongqing Medical University, along with 4019 women with benign breast diseases and 54,740 healthy females undergoing routine physical examinations in the same period. The data were stratified by age for comparison between groups. RESULTS: The prevalence of HBV infection and past infection in the breast cancer group (7.9%, 55.1%) was higher than that in the benign breast disease group (6.5%, 39.1%) and the healthy females group(5.0%, 17.6%);the rate of only HBV surface antibody positivity (HBsAb ( +)) in the breast cancer group (10.3%) was lower than that in the benign breast disease group (26.9%) and the healthy females group (49.2%), with significant differences between the three groups (p < 0.05). Stratified by age, the prevalence of HBV infection in the breast cancer group (8%, 8.9%) and benign breast disease group (7.75%, 8.1%)was higher than that in the healthy females group (4.5%, 6.3%) in the 30-39 and 40-49 age group, respectively. The past infection rate of HBV in the breast cancer group (24.8%, 45.0%) was higher than that in the benign breast disease group (16.1%, 35.4%) in the ≤ 29 and 30-39 age group, respectively.. The past infection rate of HBV in the breast cancer group was higher than that in the healthy females group in all age groups, while the rate of only HBsAb ( +) in the breast cancer group was lower than that in the benign breast disease group and the routine physical examination group in all age groups. CONCLUSIONS: Breast cancer women and women with benign breast diseases have higher rates of hepatitis B virus infection and previous infections, with more significant differences among middle-aged women. Breast cancer women and women with benign breast diseases have lower rates of only HBsAb ( +) for HBV.

4.
Artículo en Inglés | MEDLINE | ID: mdl-39001840

RESUMEN

Cholesterol is a vital component of the central nervous system and tissues, and understanding its spatial distribution is crucial for biology, pathophysiology, and diagnostics. However, direct imaging of cholesterol using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) remains challenging and time-consuming due to the difficulty in ionizing the sterol molecule. To tackle this issue, a MALDI-MSI method is established for direct and rapid analysis of the spatial distribution of cholesterol in Alzheimer's disease (AD), different cancer tissues and organs via MALDI-MSI. This excellent imaging performance depends on the study and systemic optimization of various conditions that affect the imaging of MALDI-MSI. In this case, we report the distribution and levels of cholesterol across specific structures of the AD mouse brain and different tumor tissue and organs. According to the results, the content of cholesterol in the AD mouse cerebellum, especially in the arborvitae, was significantly higher than that in the wild type (WT) model. Furthermore, we successfully visualize the distribution of cholesterol in other organs, such as the heart, liver, spleen, kidney, pancreas, as well as tumor tissues parenchyma and interstitium using MALDI-MSI. Notably, the attribution of cholesterol MS/MS hydrocarbon fragments was systematically investigated. Our presented optimization strategy and established MALDI-MSI method can be easily generalized for different animal tissues or live samples, thereby facilitating the potential for applications of MALDI-MSI in clinical, medical and biological research.

5.
Foods ; 13(13)2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38998525

RESUMEN

Estimating the impact of pesticide residue bioaccessibility in fruits on dietary exposure is a complex task in human health risk assessment. This research investigated the bioaccessibility of ten commonly used and detected pesticides in bananas and mangoes, as well as the factors influencing it, using an in vitro model. The highest bioaccessibility was observed at pH levels of 2.5 and 6.5 in the gastric and intestinal stages, respectively. Bioaccessibility decreased significantly with increasing solid/liquid ratios for most pesticides. The consumption of protein and four dietary components (carbohydrates, protein, lipids, and dietary fiber) could significantly reduce pesticide bioaccessibility by 9.89-48.32% (p < 0.05). Bioaccessibility in oral and gastric stages among four populations followed the order of adults/the elderly > children > infants, due to decreasing concentrations of α-amylase and pepsin. Pesticides in bananas generally exhibited a higher bioaccessibility (18.65-82.97%) compared to that in mangoes (11.68-87.57%). Bioaccessibility showed a negative correlation with the Log P values of the target pesticide, while no clear relationship was found between bioaccessibility and initial pesticide concentrations. Incorporating bioaccessible pesticide concentrations into risk assessments could lower dietary risk estimates by 11.85-79.57%. Assessing human exposure to pesticides based on bioaccessibility would greatly improve the accuracy of the risk assessment.

6.
Sci Rep ; 14(1): 15911, 2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-38987571

RESUMEN

In order to develop a method for the production of crack-free cladding layers, we combined surface texturing technology with laser cladding, establishing a multi-field coupled numerical simulation model. A separate investigation was conducted into the temperature, stress, and fluid fields in laser cladding processes with and without texturing, seeking optimal cladding parameters, and conducted experiments. The results of the numerical simulations indicate that pre-set texturing effectively reduces the temperature gradient during the cladding process, thereby making the thermal cycle curve smoother. The residual stresses in the X, Y, and Z directions are reduced by 34.84%, 3.94%, and 50.22%, respectively. The introduction of texturing reduces the internal flow velocity of the melt pool, preventing the occurrence of a double vortex effect. Experimental results show that the residual stresses in the X, Y, and Z directions of the predefined textured cladding layer are reduced by approximately 41%, 8%, and 47%, respectively, compared to the non-textured cladding layer. This effectively improves the surface roughness and internal grain size of the cladding layer, with no significant defects at the metallurgical bonding positions, providing a reference for future improvements in cladding layer quality.

7.
Sci Rep ; 14(1): 15420, 2024 07 04.
Artículo en Inglés | MEDLINE | ID: mdl-38965345

RESUMEN

Due to the low permeability characteristics of the deep gas-containing coal seam, the conventional prevention and control measures that cannot solve the problems of gas outbursts are unsatisfactory for the prevention and control of the coal and gas outbursts disaster. Therefore, in this study, a strain of methane-oxidizing bacteria M07 with high-pressure resistance, strong resistance, and high methane degradation rate was selected from coal mines. The growth and degradation abilities of M07 in chelating wetting agent solutions to assess its adaptability and find the optimal agent-to-M07 ratio. It provides a new method for integrating the reduction of impact tendency and gas pressure in deep coal mines. The experimental results show that M07 is a Gram-positive bacterium of the genus Bacillus, which has strong resistance and adaptability to high-pressure water injection. By degrading 70 mol of methane, M07 produces 1 mol of carbon dioxide, which can reduce gas pressure and reduce the risk of gas outbursts in coal mines. As the experiment proves, the best effect was achieved when the M07 concentration of the chelating wetting agent was 0.05%. The methane-oxidizing bacteria based on the chelating wetting agent as carriers prove a new prevention and control method for the integrated prevention and control of coal and gas outbursts in coal mines and also provide a new idea for microbial application in coal mine disaster control.


Asunto(s)
Biodegradación Ambiental , Quelantes , Metano , Metano/metabolismo , Metano/química , Quelantes/química , Quelantes/farmacología , Quelantes/metabolismo , Bacillus/metabolismo , Carbón Mineral , Minas de Carbón
8.
Can J Anaesth ; 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-39042215

RESUMEN

PURPOSE: Opioids remain the mainstay of analgesia for critically ill patients, but its exposure is associated with negative effects including persistent use after discharge. Nonsteroidal anti-inflammatory drugs (NSAIDs) may be an effective alternative to opioids with fewer adverse effects. We aimed to describe beliefs and attitudes towards the use of NSAIDs in adult intensive care units (ICUs). METHODS: Our survey of Canadian ICU physicians was conducted using a web-based platform and distributed through the Canadian Critical Care Society (CCCS) email distribution list. We used previously described survey development methodology including question generation and reduction, pretesting, and clinical sensibility and pilot testing. RESULTS: We received 115 completed surveys from 321 CCCS members (36%). Nonsteroidal anti-inflammatory drugs use was most described as "rarely" (59 respondents, 51%) with the primary concern being adverse events (acute kidney injury [108 respondents, 94%] and gastrointestinal bleeding [92 respondents, 80%]). The primary preferred analgesic was acetaminophen (75 respondents, 65%) followed by opioids (40 respondents, 35%). Most respondents (91 respondents, 80%) would be willing to participate in a randomized controlled trial examining NSAID use in critical care. CONCLUSIONS: In our survey, Canadian critical care physicians did not mention commonly using NSAIDs primarily because of concerns about adverse events. Nevertheless, respondents were interested in further studying ketorolac, a commonly used NSAID outside of the ICU, in critically ill patients.


RéSUMé: OBJECTIF: Les opioïdes restent le pilier de l'analgésie pour les patient·es gravement malades, mais l'exposition à ces agents est associée à des effets négatifs, notamment à leur utilisation persistante après le congé de l'hôpital. Les anti-inflammatoires non stéroïdiens (AINS) pourraient constituer une alternative efficace aux opioïdes avec moins d'effets indésirables. Nous avons cherché à décrire les croyances et les attitudes à l'égard de l'utilisation des AINS dans les unités de soins intensifs (USI) pour adultes. MéTHODE: Notre sondage auprès des médecins intensivistes au Canada a été mené à l'aide d'une plateforme Web et distribué aux personnes sur la liste de distribution électronique de la Société canadienne de soins intensifs (SCSI). Nous avons utilisé une méthodologie d'élaboration d'enquêtes décrite précédemment, y compris la génération et la réduction de questions, les tests préalables, la sensibilité clinique et les tests pilotes. RéSULTATS: Nous avons reçu 115 sondages remplis par 321 membres de la SCSI (36 %). L'utilisation d'anti-inflammatoires non stéroïdiens a été décrite comme « rare ¼ (59 répondant·es, 51 %), la principale préoccupation étant les événements indésirables (insuffisance rénale aiguë [108 répondant·es, 94 %] et saignements gastro-intestinaux [92 répondant·es, 80 %]). Le principal analgésique préféré était l'acétaminophène (75 répondant·es, 65 %), suivi des opioïdes (40 répondant·es, 35 %). La plupart des répondant·es (91 répondant·es, 80 %) seraient prêt·es à participer à une étude randomisée contrôlée examinant l'utilisation des AINS en soins intensifs. CONCLUSION: Dans notre sondage, les médecins intensivistes au Canada n'ont pas mentionné l'utilisation courante d'AINS, principalement en raison de préoccupations concernant leurs effets indésirables. Néanmoins, les répondant·es étaient intéressé·es à étudier plus avant le kétorolac, un AINS couramment utilisé en dehors des soins intensifs, chez les patient·es gravement malades.

9.
Vet Med Sci ; 10(4): e1470, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38923734

RESUMEN

BACKGROUND: The intestine of young ruminants is in the developmental stage and has weaker resistance to the changes of external environment. Improving intestinal health is vital to promoting growth of young ruminants. This study investigated effects of guanidino acetic acid (GAA) and rumen-protected betaine (RPB) supplementation on growth, dietary nutrient digestion and GAA metabolism in the small intestine of sheep. METHODS: Eighteen healthy Kazakh rams (27.46 ± 0.10 kg of body weight and 3-month old) were categorized into control, test group I and test group II, which were fed a basal diet, 1500 mg/kg GAA and 1500 mg/kg GAA + 600 mg/kg RPB, respectively. RESULTS: Compared with control group, test group II had increased (p < 0.05) average daily gain, plasma creatine level, ether extract (EE) and phosphorus digestibility on day 30. On day 60, the EE apparent digestibility, jugular venous plasma GAA, GAA content in the duodenal mucosa and GAA content in the jejunal and ileal mucosa of test group II were higher (p < 0.05) than other groups. Transcriptome analysis revealed that the differentially expressed genes (DEGs) involved in the duodenal pathways of oxidative phosphorylation and non-alcoholic fatty liver disease were significantly altered in test group II versus test group I (p < 0.05). Moreover, in the jejunum, the MAPK signalling pathway, complement and coagulation cascade and B-cell receptor signalling pathway were significantly enriched, with ATPase, solute carrier transporter protein, DHFR, SI, GCK, ACACA and FASN being the significantly DEGs (p < 0.05). CONCLUSION: Dietary supplementation of RPB on top of GAA in sheep diets may promote sheep growth and development by improving the body's energy, amino acid, glucose and lipid metabolism capacity.


Asunto(s)
Alimentación Animal , Betaína , Creatina , Dieta , Suplementos Dietéticos , Digestión , Glicina , Animales , Suplementos Dietéticos/análisis , Betaína/metabolismo , Betaína/administración & dosificación , Alimentación Animal/análisis , Dieta/veterinaria , Masculino , Digestión/efectos de los fármacos , Creatina/metabolismo , Glicina/análogos & derivados , Glicina/administración & dosificación , Glicina/metabolismo , Ovinos/fisiología , Ovinos/metabolismo , Oveja Doméstica/fisiología , Oveja Doméstica/metabolismo , Fenómenos Fisiológicos Nutricionales de los Animales/efectos de los fármacos , Distribución Aleatoria , Nutrientes/metabolismo
10.
Langmuir ; 40(27): 14118-14129, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38913660

RESUMEN

Gravity is essential for the shedding of condensed droplets on hydrophobic surfaces, whose influences on condensation parameters under unconventional gravity conditions remain unclear and are hard to probe through experiments. A simulation framework is designed here to investigate such phase-change processes. We find clear scaling laws between heat flux Q, residual volume V, gravitational acceleration g, and nucleation density N0 with Q ∼ g1/6N01/3 and V ∼ g-1/2N00. We also identify a critical gravitational acceleration determined by nucleation density, above which a counterintuitive trend emerges: the heat flux decreases with increasing gravitational acceleration. This deviation is attributed to the sharp decrease in heat flux contributed by droplets larger than the effective radius. In addition, for zero-gravity scenarios, a centrifugal strategy is proposed to simulate Earth's gravity by introducing artificial gravity with a spatial gradient. We reveal that the gradients have a significant influence on the residual volume but a minor one on the heat flux. The conclusions are informative for the estimation and design of condensation heat transfer systems for future space applications.

11.
Nat Commun ; 15(1): 5277, 2024 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-38902274

RESUMEN

The synthesis of chiral α-azaheteroaryl oxiranes via enantioselective catalysis is a formidable challenge due to the required complex stereoselectivity and diverse N-heterocyclic structures. These compounds play a crucial role in developing bioactive molecules, where precise chirality significantly influences biological activity. Here we show that using chiral phosphoric acid as a catalyst, our method efficiently addresses these challenges. This technique not only achieves high enantio- and diastereoselectivity but also demonstrates superior chemo- and stereocontrol during the epoxidation of alkenyl aza-heteroarenes. Our approach leverages a synergistic blend of electrostatic and hydrogen-bonding interactions, enabling the effective activation of both substrates and hydrogen peroxide. The resulting chiral oxiranes exhibit enhanced diversity and functionality, aiding the construction of complex chiral azaaryl compounds with contiguous stereocenters. Kinetic and density functional theory studies elucidate the mechanism, highlighting chiral phosphoric acid's pivotal role in this intricate enantioselective process.

12.
J Environ Manage ; 363: 121411, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38861887

RESUMEN

Rural areas are the main source of ecosystem services in arid and semi-arid areas, and ecosystem services are the background conditions for rural revitalization. In this study, the spatial pattern of key ecosystem services in the countryside was assessed, and the trade-offs and synergistic relationships among ecosystem services were investigated, using the Tacheng-Emin Basin in China as the study area. Finally, the types of ecological function zoning and development strategies for the countryside are proposed. The results showed that: (1) the area of ecological land was large, and the average land use intensity was 2.48, which belonged to the medium intensity. (2) The mean values of the six ecosystem services are all in the middle and lower classes, and the spatial distribution of the five ecosystem services is similar, except for food production. (3) Except for grain production, the other five ecosystem services showed positive feedback to elevation. The other five ecosystem services are synergistic, and there are trade-offs between grain production and other ecosystem services. In the nonlinear interaction mechanism of ecosystem services, the fluctuation constraint occupies the largest proportion. (4) At smaller spatial scales, there are more types of ecosystem service clusters. Combining the results of the study, the villages in the study area can be categorized into five types. This study formulates five priority levels of rural ecological revitalization and proposes different development recommendations for the sustainable development of each type of village. This study is helpful for the fine management of land resources and the revitalization of rural ecology and provides a reference for the sustainable development of ecosystem services in arid and semi-arid areas.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , China , Ecología
13.
Opt Lett ; 49(12): 3360-3363, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38875620

RESUMEN

Chaotic time series prediction has attracted much attention in recent years because of its important applications, such as security analysis for random number generators and chaos synchronization in private communications. Herein, we propose a BLSTM convolution and self-attention network model to predict the optical chaos. We validate the model's capability for direct and recursive prediction, and the model dramatically reduces the accumulation of errors. Moreover, the time duration prediction of optical chaos is increased with comparative accuracy where the predicted sequence length reaches 4 ns with normalized mean squared error (NMSE) of less than 0.01.

14.
ACS Omega ; 9(22): 23451-23461, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38854512

RESUMEN

Previous studies on supercavitation flow have primarily focused on a standing water environment, neglecting the impact of periodic disturbance in a marine environment. Therefore, a series of periodic functions with different frequencies and amplitudes are defined to simulate the periodic disturbance, and a slender projectile is adopted to numerically study the effect of the periodic disturbance on the supercavitation phenomenon in this paper. Research results show that the cavity profile evolves periodically with the periodic disturbance of the external flow field. At the same time, as the frequency and amplitude increase, the minimum cavity shape gradually decreases to the point that the projectile cannot be wholly enveloped, and the maximum cavity profile gradually increases. Furthermore, the relationship between the cavity length (l i ) and the frequency (f) when the cavity cannot envelop the projectile is obtained (l i = -7.381f + 215.384). Meanwhile, the critical frequency range (7.16 ≤ f < 7.96) and amplitude range (1.1 ≤ am < 1.22) of the cavity to envelop the projectile are obtained. The key factors of periodic disturbances on supercavitation flow are revealed in this paper, which provides a theoretical foundation for maintaining supercavitation flow stability in an environment of periodic disturbance flow.

16.
RSC Adv ; 14(28): 19718-19725, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38899034

RESUMEN

The mechanical strength of magnesium implants undergoes a rapid decline after implantation due to bioabsorption, which can lead to the risk of rupture. To ensure sustained mechanical strength and initiate bioabsorption selectively upon specific external stimuli until the bone regains sufficient support, we developed a biosafe near-infrared light (NIR)-sensitive polymer coating using polycaprolactone (PCL) and Ti3C2 (MXenes). The synthetic MXene powders were characterized using SEM, EDS, and XRD, and the amount of MXenes had a proliferation-promoting effect on MC3T3-E1, as observed through cell assays. The PCL-MXene coating was successfully prepared on the magnesium surface using the casting coating method, and it can protect the magnesium surface for up to 28 days by decreasing the corrosion ratio. However, the coating can be easily degraded after exposure to NIR light for 20 minutes to expose the magnesium substrate, especially in a liquid environment. Meanwhile, the magnesium implant with the PCL-MXene coating has no cytotoxicity toward MC3T3-E1. These findings can provide a new solution for the development of controlled degradation implants.

17.
ACS Appl Mater Interfaces ; 16(24): 31567-31575, 2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38836291

RESUMEN

Solar energy is widely used in photovoltaic power generation as a kind of clean energy. However, the liquid film, frosting, and icing on the photovoltaic module seriously limit the efficiency of photovoltaic power generation. We developed a composite coating (Y6-NanoSH) by combining an in situ photothermal and transparent Y6 organic film with a nanosuperhydrophobic material. The Y6-NanoSH coated glass exhibited excellent optical clarity both indoors and outdoors, indicating that the coating holds great promise in anti-icing applications for photovoltaic panels. The Y6-NanoSH coating absorbs very little visible light but instead absorbs in the near-infrared region, thereby emitting heat. When exposed to sunlight, the Y6-NanoSH coated photovoltaic panel raises its surface temperature, inhibiting the growth and accumulation of ice and frost on its surface. This is achieved through a combination of photothermal emission and superhydrophobic repellency, which promotes the evaporation and rolling away of water droplets. This validates our success in developing a photothermal, transparent, and superhydrophobic coating with excellent anti-icing capabilities, suitable for use on photovoltaic panels, as well as potential applications in car windscreens, transmission lines, curtain walls, and weather radomes.

18.
AJOG Glob Rep ; 4(2): 100331, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38919705

RESUMEN

BACKGROUND: Postpartum readmission is an important indicator of postpartum morbidity. The likelihood of postpartum readmission is highest for Black individuals. However, it is unclear whether the likelihood of postpartum readmission has changed over time according to race/ethnicity. Little is also known about the factors that contribute to these trends. OBJECTIVE: This study aimed to: (1) examine trends in postpartum readmission by race/ethnicity, (2) examine if prenatal or clinical factors explain the trends, and (3) investigate if racial/ethnic disparities changed over time. STUDY DESIGN: We examined trends in postpartum readmission, defined as hospitalization within 42 days after birth hospitalization discharge, using live birth and fetal death certificates linked to delivery discharge records from 10,711,289 births in California from 1997 to 2018. We used multivariable logistic regression models that included year and year-squared (to allow for nonlinear trends), overall and stratified by race/ethnicity, to estimate the annual change in postpartum readmission during the study period, represented by odds ratios and 95% confidence intervals. We then adjusted models for prenatal (eg, patient demographics) and clinical (eg, gestational age, mode of birth) factors. To determine whether racial/ethnic disparities changed over time, we calculated risk ratios for 1997 and 2018 by comparing the predicted probabilities from the race-specific, unadjusted logistic regression models. RESULTS: The overall incidence of postpartum readmission was 10 per 1000 births (17.4/1000 births for non-Hispanic Black, 10/1000 for non-Hispanic White, 7.9/1000 for non-Hispanic Asian/Pacific Islander, and 9.6/1000 for Hispanic individuals). Odds of readmission increased for all groups during the study period; the increase was greatest for Black individuals (42% vs 21%-29% for the other groups). After adjustment for prenatal and clinical factors, the increase in odds was similar for Black and White individuals (12%). The disparity in postpartum readmission rates relative to White individuals increased for Black individuals (risk ratio, 1.68 in 1997 and 1.90 in 2018) and more modestly for Hispanic individuals (risk ratio, 1.02 in 1997 and 1.05 in 2018) during the study period. Asian/Pacific Islander individuals continued to have lower risk than White individuals during the study period (risk ratio, 0.87 in 1997 and 0.82 in 2018). CONCLUSION: The rate of postpartum readmissions increased from 1997 to 2018 in California across all racial/ethnic groups, with the greatest increase observed for Black individuals. Racial/ethnic differences in the trend were more modest after adjustment for prenatal and clinical factors. It is important to find ways to prevent further increases in postpartum readmission, especially among groups at highest risk.

19.
Environ Sci Pollut Res Int ; 31(25): 37245-37255, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38767795

RESUMEN

In mid-November 2021, there were large areas of white rot disease on cultivated Saccharina japonica in Rongcheng City, China, and diseases were undetected on Sargassum horneri and Porphyra yezoensis. The disturbance direction of bacterial community in the phycosphere after disease outbreak and the relationship with seawater nutrients remain unclear. Here, in situ studies of bacterial community in the non-diseased and diseased areas (Shawo and Dongchu islands) and seawater nutrient levels were carried out. 16S rRNA sequencing showed that the bacterial richness of the studied seaweeds increased in the diseased area. Only in S. japonica, Algitalea outcompeted abundant primary bacteria with probiotic relationships to the host of the non-diseased area, and dominated in the diseased area (17.6% of the total abundance). Nitrogen and phosphorus levels in seawater were 57.8% and 19.6% higher in the non-diseased area than those in the diseased area, respectively, and were strongly correlated with the phycosphere bacteria at the family level of S. japonica. There was no difference in potential pathogenicity between the two areas, while positive signal communications decreased, and nitrogen cycle, chemoheterotrophy, and cellulolysis increased in the diseased area compared to the non-diseased area. Overall, white rot disease caused a structural disturbance in phycosphere bacterial community of S. japonica that related to seawater nutrient levels. Enriched degraders and altered bacterial community functions may exacerbate the disease. This evaluation will provide information for white rot disease management to prevent and mitigate the occurrence of S. japonica outbreaks.


Asunto(s)
Agua de Mar , Agua de Mar/microbiología , China , ARN Ribosómico 16S , Bacterias , Fósforo , Nitrógeno , Algas Marinas/microbiología , Nutrientes , Algas Comestibles , Laminaria
20.
BMC Microbiol ; 24(1): 177, 2024 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-38783194

RESUMEN

BACKGROUND: Clostridioides difficile is the main pathogen of antimicrobial-associated diarrhoea and health care facility-associated infectious diarrhoea. This study aimed to investigate the prevalence, toxin genotypes, and antibiotic resistance of C. difficile among hospitalized patients in Xi'an, China. RESULTS: We isolated and cultured 156 strains of C. difficile, representing 12.67% of the 1231 inpatient stool samples collected. Among the isolates, tcdA + B + strains were predominant, accounting for 78.2% (122/156), followed by 27 tcdA-B + strains (27/156, 17.3%) and 6 binary toxin gene-positive strains. The positive rates of three regulatory genes, tcdC, tcdR, and tcdE, were 89.1% (139/156), 96.8% (151/156), and 100%, respectively. All isolates were sensitive to metronidazole, and the resistance rates to clindamycin and cephalosporins were also high. Six strains were found to be resistant to vancomycin. CONCLUSION: Currently, the prevalence rate of C. difficile infection (CDI) in Xi'an is 12.67% (156/1231), with the major toxin genotype of the isolates being tcdA + tcdB + cdtA-/B-. Metronidazole and vancomycin were still effective drugs for the treatment of CDI, but we should pay attention to antibiotic management and epidemiological surveillance of CDI.


Asunto(s)
Antibacterianos , Toxinas Bacterianas , Clostridioides difficile , Infecciones por Clostridium , Heces , Genotipo , Hospitales , Clostridioides difficile/genética , Clostridioides difficile/efectos de los fármacos , Clostridioides difficile/aislamiento & purificación , Clostridioides difficile/clasificación , Humanos , China/epidemiología , Antibacterianos/farmacología , Infecciones por Clostridium/microbiología , Infecciones por Clostridium/epidemiología , Toxinas Bacterianas/genética , Hospitales/estadística & datos numéricos , Heces/microbiología , Farmacorresistencia Bacteriana/genética , Prevalencia , Pruebas de Sensibilidad Microbiana , Femenino , Persona de Mediana Edad , Masculino , Anciano , Adulto , Proteínas Bacterianas/genética , Diarrea/microbiología , Diarrea/epidemiología , Metronidazol/farmacología , Adulto Joven , Enterotoxinas/genética , Adolescente , Vancomicina/farmacología , Clindamicina/farmacología , Anciano de 80 o más Años
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