Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 86
Filtrar
1.
J Am Chem Soc ; 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38859580

RESUMO

In the realm of organic synthesis, the catalytic and stereoselective formation of C-glycosidic bonds is a pivotal process, bridging carbohydrates with aglycones. However, the inherent chirality of the saccharide scaffold often has a substantial impact on the stereoinduction imposed by a chiral ligand. In this study, we have established an unprecedented zirconaaziridine-mediated asymmetric nickel catalysis, enabling the diastereoselective coupling of bench-stable glycosyl phosphates with a range of (hetero)aromatic and glycal iodides as feasible coupling electrophiles. Our developed method showcases a broad scope and a high tolerance for various functional groups. More importantly, precise stereocontrol toward both anomeric configurations of forming C(sp2)-glycosides can be realized by simply utilizing the popular chiral bioxazoline (biOx) ligands in this reductive Ni catalysis. Regarding the operating mechanism, both experimental and computational studies support the occurrence of a redox transmetalation process, leading to the formation of a transient, bimetallic Ni-Zr species that acts as a potent and efficient single-electron reductant in the catalytic process.

2.
J Affect Disord ; 359: 59-69, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38768819

RESUMO

OBJECTIVE: This study intends to explore the effect of depressive symptoms on adverse clinical outcomes in middle-aged and elderly hypertensive patients. METHODS: This post hoc analysis was conducted using data from the Systolic Blood Pressure Intervention Trial (SPRINT), and we used cox proportional risk regression to examine the relationship between depressive symptoms and adverse clinical outcomes (primary outcome, all-cause mortality, cardiovascular disease(CVD) mortality, heart failure(HF), myocardial infarction(MI), non-myocardial infarction acute coronary syndrome(non-MI ACS)). RESULTS: In a follow-up study of 9259 participants, we found that depression symptoms was significantly and positively associated with the primary outcome (HR 1.03, 95%CI 1.01-1.05; p for trend = 0.0038), all-cause mortality (HR 1.03, 95%CI 1.01-1.05; p for trend = 0.0308), HF(HR 1.05, 95%CI 1.01-1.08; p for trend = 0.0107), and non-MI ACS(HR 1.06, 95%CI 1.01-1.10; p for trend = 0.0120). Kaplan-Meier survival curves for depression symptoms severity (none, mild, moderate, and above) and adverse clinical outcomes suggested that for all but primary clinical outcomes, the cumulative risk of adverse clinical outcomes increased with increasing depression symptoms severity. CONCLUSION: For middle-aged and elderly hypertensive patients, depression symptoms exacerbates the risk of adverse clinical outcomes (primary outcome, all-cause mortality, CVD death, MI, HF, and non-MI ACS), and the risk increases with the severity of depression symptoms.


Assuntos
Depressão , Hipertensão , Infarto do Miocárdio , Humanos , Hipertensão/epidemiologia , Feminino , Masculino , Pessoa de Meia-Idade , Idoso , Depressão/epidemiologia , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/psicologia , Infarto do Miocárdio/epidemiologia , Insuficiência Cardíaca/mortalidade , Seguimentos , Doenças Cardiovasculares/mortalidade , Doenças Cardiovasculares/epidemiologia , Modelos de Riscos Proporcionais , Síndrome Coronariana Aguda/mortalidade , Síndrome Coronariana Aguda/complicações , Síndrome Coronariana Aguda/psicologia
3.
Am J Med Sci ; 2024 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-38705462
5.
Arch Microbiol ; 206(4): 171, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38491219

RESUMO

A Gram-negative, facultatively anaerobic, short rod-shaped bacterium, designated as strain HZ0627T, was isolated from the appendiceal pus of a patient with appendicitis in Yongzhou, Hunan, China. This strain was subjected to comprehensive phenotypic, phylogenetic, and genomic analyses using polyphasic taxonomic methods. Phylogenetic analysis of the 16S rRNA gene sequence revealed that this strain belonged to the genus Proteus and the family Morganellaceae, whereas that based on the rpoB gene sequence and phylogenomic analysis demonstrated that this strain was distinctly separated from other type strains of Proteus species. Moreover, whole-genome-based analyses, including in silico DNA-DNA hybridization (isDDH) and average nucleotide identity (ANI), revealed that strain HZ0627T had much lower isDDH rates (24.5-55.6%) and ANI (82.04-93.90%) than those of the thresholds (i.e., 70% and 95%, respectively) for species delineation, when compared to the type strains of other Proteus species. The cellular fatty acid profile of strain HZ0627T was dominated by C16:0 (34.5%), cyclo C17:0 (25.8%), C14:0 (12.6%), C16:1 iso I/14:0 3-OH (7.7%), C18:1ω7c/18:1ω6c (6.5%), and C16:1ω7c/16:1ω6c (4.9%), which clearly differentiated it from the documented type strains of Proteus species. In addition, several specific physiological traits, including optimal growth temperature, tolerance to sodium chloride, and carbon source utilization, differed from those of other Proteus species. Therefore, we propose the name Proteus appendicitidis sp. nov. for strain HZ0627T (= CCTCC AB 2022380T = KCTC 92986T), which represents the type strain of this novel Proteus species.


Assuntos
Apendicite , Humanos , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Proteus/genética , Ácidos Graxos/análise , China , DNA , Supuração , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Hibridização de Ácido Nucleico
6.
Chemosphere ; 353: 141498, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38382720

RESUMO

This study used an innovative synergistic microbial and insect approach to treat maize straw and kitchen waste substrates, including cyclic microbial fermentation and feeding of black soldier fly larvae (BSFL) using the fermented substrate. Increasing cycle numbers led to significantly increased cellulose, hemicellulose, and lignin degradation rates (DR) in the maize straw, which increased by 68.28%, 81.43% and 99.95%, respectively, compared to those in the blank group without frass addition. Moreover, according to the experimental results, it was revealed that the structure of lignocellulose, the composition and structure of the bacterial community in the BSFL gut and frass changed significantly after the addition of the previous cycle of frass treatment. Moreover, the differences in amplicon sequence variants (ASVs) between the gut and frass further increased. The relative abundances of Enterococcus and Actinobacteria in the gut and Gammaproteobacteria_unclassified and Dysgonomonas in the frass increased significantly, which may play a more positive role in lignocellulose degradation. In conclusion, this study showed that frass fermentation + BSFL feeding to degrade straw is a promising method and that frass fermentation is beneficial for the whole cycle. Furthermore, these findings underscore the beneficial impact of frass fermentation on the entire cycle.


Assuntos
Dípteros , Zea mays , Animais , Zea mays/metabolismo , Fermentação , Larva/metabolismo , Celulose/metabolismo , Bactérias/genética , Bactérias/metabolismo
8.
Front Microbiol ; 14: 1294056, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38029150

RESUMO

The global COVID-19 pandemic has presented a significant, ongoing challenge since its emergence in late 2019. Today, the Omicron strain, which is less lethal but more contagious than the original outbreak strain, continues to pose substantial health risks. In this background, the management of psoriatic comorbidities has become even more complex, particularly for patients with underlying inflammatory, metabolic, or cardiovascular diseases. This review aims to summarize current research on comorbid COVID-19 and psoriasis, and provide insights into the development of evidence-based management strategies. By providing appropriate patient instruction, implementing protective measures, and re-evaluating medication prescriptions based on each patient's unique situation, healthcare professionals can effectively address the challenges faced by patients with comorbid psoriasis in the COVID-19 era.

9.
J Laparoendosc Adv Surg Tech A ; 33(12): 1193-1200, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37787912

RESUMO

Background: The purpose of this study was to investigate the relationship between malnutrition assessed by the Global Leadership Initiative on Malnutrition (GLIM) criteria and the occurrence of severe postoperative complications (SPCs) after gastrectomy in patients with gastric cancer. Methods: A total of 220 patients with gastric cancer were included in this retrospective study. According to the GLIM criteria, the first step was to use the Nutrition Risk Screening Score 2002 to conduct nutritional risk screening for patients and the second step was to diagnose and grade the severity of malnutrition in patients at risk of malnutrition. According to the Clavien-Dindo classification system, SPCs were defined as C-D Grade IIIa or higher. Results: Overall, 66 (30.0%) patients were diagnosed with malnutrition, including 32 (14.5%) with moderate malnutrition and 34 (15.5%) with severe malnutrition. The incidence of SPCs was 14.5%, and the most frequent postoperative event was anastomotic leakage. In the multivariate regression analysis, malnutrition was considered an independent risk factor for SPCs (P < .001). After adjusting for various factors, the grading association remained statistically significant. Compared with patients with normal nutrition, patients with moderate and severe malnutrition have a nearly 15-fold (OR = 15.682, 95% CI: 4.481-54.877, P < .001) and 20-fold (OR = 20.554, 95% CI: 5.771-73.202, P < .001) increased risk of developing SPCs, respectively. Conclusions: Malnutrition assessed by GLIM was an independent risk factor for SPCs in gastric cancer patients. Therefore, early identification of malnourished patients is crucial for timely implementation of nutritional treatment and reducing the occurrence of postoperative complications.


Assuntos
Desnutrição , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/complicações , Neoplasias Gástricas/cirurgia , Liderança , Estudos Retrospectivos , Desnutrição/diagnóstico , Complicações Pós-Operatórias/epidemiologia , Gastrectomia/efeitos adversos , Avaliação Nutricional , Estado Nutricional
10.
Nat Chem ; 15(9): 1276-1284, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37106096

RESUMO

The composition, sequence, length and type of glycosidic linkage of polysaccharides profoundly affect their biological and physical properties. However, investigation of the structure-function relationship of polysaccharides is hampered by difficulties in accessing well-defined polysaccharides in sufficient quantities. Here we report a chemical approach to precision polysaccharides with native glycosidic linkages via living cationic ring-opening polymerization of 1,6-anhydrosugars. We synthesized well-defined polysaccharides with tunable molecular weight, low dispersity and excellent regio- and stereo-selectivity using a boron trifluoride etherate catalyst and glycosyl fluoride initiators. Computational studies revealed that the reaction propagated through the monomer α-addition to the oxocarbenium and was controlled by the reversible deactivation of the propagating oxocarbenium to form the glycosyl fluoride dormant species. Our method afforded a facile and scalable pathway to multiple biologically relevant precision polysaccharides, including D-glucan, D-mannan and an unusual L-glucan. We demonstrated that catalytic depolymerization of precision polysaccharides efficiently regenerated monomers, suggesting their potential utility as a class of chemically recyclable materials with tailored thermal and mechanical properties.


Assuntos
Fluoretos , Polissacarídeos , Polimerização , Polissacarídeos/química , Glucanos , Catálise
11.
Angew Chem Int Ed Engl ; 62(27): e202300768, 2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37002927

RESUMO

The accumulation of plastic waste, due to lack of recycling, has led to serious environmental pollution. Although mechanical recycling can alleviate this issue, it inevitably reduces the molecular weight and weakens the mechanical properties of materials and is not suitable for mixed materials. Chemical recycling, on the other hand, breaks the polymer into monomers or small-molecule constituents, allowing for the preparation of materials of quality comparable to that of the virgin polymers and can be applied to mixed materials. Mechanochemical degradation and recycling leverages the advantages of mechanical techniques, such as scalability and efficient energy use, to achieve chemical recycling. We summarize recent progress in mechanochemical degradation and recycling of synthetic polymers, including both commercial polymers and those designed for more efficient mechanochemical degradation. We also point out the limitations of mechanochemical degradation and present our perspectives on how the challenges can be mitigated for a circular polymer economy.

12.
Photodiagnosis Photodyn Ther ; 42: 103545, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37001715

RESUMO

BACKGROUND: Hemoporfin-mediated photodynamic therapy (Hemoporfin-PDT) has been approved for port-wine stain (PWS) in China in 2017. This study evaluated the efficacy and safety of Hemoporfin-PDT for PWS in a real life setting and investigated factors that influence the efficacy. METHODS: A multicenter retrospective study included patients with PWS who underwent Hemoporfin-PDT in 29 hospitals across China and completed at least two months of follow-up. The efficacy was evaluated based on patien photographs. RESULTS: A total of 1679 patients were included. After the first and second sessions of Hemoporfin-PDT, 63.5 and 75.3% of patients responded, respectively. The response rate of purple-type PWS was significantly lower than that of pink-type PWS (OR: 0.71, 95% CI: 0.54-0.94, P < 0.05), and there was no significant difference between thick- and pink-type (OR: 0.72, 95% CI: 0.42-1.22, P > 0.05). The response rate of PWS on the limbs was significantly lower than that on the mid-face (OR: 0.35, 95% CI: 0.23-0.53, P < 0.0001), while no significant difference was observed between PWS on the peripheral part of the face, neck or other parts of the body and PWS on the mid-face (P > 0.05). The response rate was lower in male patients with an age > 3 years or ≤ 6 years (P < 0.05). Previous treatment history did not affect the efficacy (P > 0.05). Hemoporfin-PDT was well tolerated. CONCLUSION: Patients with PWS have a good response and good tolerance to Hemoporfin-PDT.


Assuntos
Fotoquimioterapia , Mancha Vinho do Porto , Humanos , Masculino , Pré-Escolar , Fotoquimioterapia/métodos , Mancha Vinho do Porto/tratamento farmacológico , Fármacos Fotossensibilizantes/uso terapêutico , Estudos Retrospectivos , Hematoporfirinas
13.
Front Microbiol ; 14: 1128057, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36891380

RESUMO

Introduction: Cyanogenic glycosides (CNglcs) are bioactive plant products involving in plant defense against herbivores by virtue of their abilities to release toxic hydrogen cyanide (HCN). Aspergillus niger has been shown to be effective in producing ß-glucosidase, which could degrade CNglcs. However, whether A. niger could remove CNglcs under ensiling conditions is still unknown. Methods: In this study, we first investigated the HCN contents in ratooning sorghums for two years, then the sorghums were ensiled with or without the addition of A. niger. Results: Two years' investigation indicated that the contents of HCN in fresh ratooning sorghum were larger than 801 mg/kg FW (fresh weight), which could not be reduced by silage fermentation under safety threshold (200 mg/kg FW). A. niger could produce ß-glucosidase over a range of pH and temperature, which degraded the CNglcs and removed the hydrogen cyanide (HCN) at early days of ratooning sorghum fermentation. The addition of A. niger (2.56 × 107 CFU/ml) altered the microbial community, increased bacterial diversity, improved the nutritive qualities, and reduced the HCN contents in ensiled ratooning sorghum lower than 100 mg/kg FW after 60 days of fermentation. Overall, the addition of 150 ml A. niger + 50 ml sterile water per 3 kg silage could efficiently remove CNglcs from ratooning sorghum silage. Conclusion: In conclusion, A. niger could produce ß-glucosidase which degraded the CNglcs during the early days of fermentation, benefiting the ensiling process and improving the utilization of ratooning sorghum.

15.
Nat Commun ; 14(1): 225, 2023 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-36641481

RESUMO

Polymers with low ceiling temperatures (Tc) are highly desirable as they can depolymerize under mild conditions, but they typically suffer from demanding synthetic conditions and poor stability. We envision that this challenge can be addressed by developing high-Tc polymers that can be converted into low-Tc polymers on demand. Here, we demonstrate the mechanochemical generation of a low-Tc polymer, poly(2,5-dihydrofuran) (PDHF), from an unsaturated polyether that contains cyclobutane-fused THF in each repeat unit. Upon mechanically induced cycloreversion of cyclobutane, each repeat unit generates three repeat units of PDHF. The resulting PDHF completely depolymerizes into 2,5-dihydrofuran in the presence of a ruthenium catalyst. The mechanochemical generation of the otherwise difficult-to-synthesize PDHF highlights the power of polymer mechanochemistry in accessing elusive structures. The concept of mechanochemically regulating the Tc of polymers can be applied to develop next-generation sustainable plastics.


Assuntos
Ciclobutanos , Polímeros , Polímeros/química , Plásticos , Catálise
16.
Skin Res Technol ; 29(1): e13219, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36331142

RESUMO

OBJECTIVES: Due to a recent development of high-frequency ultrasound (HFUS) systems, it is easier to realize high-resolution in vivo imaging of the biological tissues. The object of this study was to map the thickness and echo density of skin layers in healthy Chinese people and assess the influence of gender, age, and region on it. METHODS: A total of 189 volunteers (85 male, 104 female) with age range of 22-75-year old (mean age of 41.2-year old) were enrolled. The thickness and density of the epidermis and dermis layer were detected by high-frequency (22 or 75 MHz) ultrasonography at 13 different anatomical sites, including the forehead, cheeks, flexor and extensor forearms, flexor and extensor upper arms, inner and outer legs, inner and outer thighs, back, and abdomen. RESULTS: The thickness and density of epidermis/dermis between different anatomical sites were statistically significant (p < 0.05). The epidermis thickness of the face and trunk were less than that of the limbs, whereas the thicknesses of the dermis were on the contrary. The density of the epidermis/dermis of the face and trunk were less than that of the limbs. The thickness of dermis in most of the sites were higher in male than in female, and the density of epidermis and dermis in most of the sites were less in men than in women. The thicknesses/densities of dermis were lower in older age group in almost all sites, whereas only several sites reached statistical. The difference between the north and south regions showed the environment also influenced the thickness and density of the skin. CONCLUSION: HFUS provides a simple noninvasive method for evaluating the skin thickness and echo-density, which, reflecting intradermal structure, exhibit systematic regional variation. With the establishment of Chinese phenotypic database of skin thickness and density, it will be helpful for the skin disease assessment, skin surgery, and cosmetology technology.


Assuntos
População do Leste Asiático , Pele , Humanos , Masculino , Feminino , Idoso , Adulto , Adulto Jovem , Pessoa de Meia-Idade , Pele/diagnóstico por imagem , Epiderme/diagnóstico por imagem , Ultrassonografia/métodos , Células Epidérmicas
17.
Chem Asian J ; 18(3): e202201133, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36534946

RESUMO

Chemically recyclable polymers offer a promising solution to address the issues associated with the unsustainable use of plastics by converting the traditional linear plastic economy into a circular one. Central to developing chemically recyclable polymers is to identify the appropriate monomers that enable practical conditions for polymerization and depolymerization and ensure useful stability and material properties. Our group has recently demonstrated that trans-cyclobutane-fused cyclooctene (tCBCO) meets the abovementioned requirements and is a promising candidate for developing chemically recyclable polymers. Herein, encouraged by the success with tCBCO, we investigate the thermodynamics of polymerization of a relevant system, trans-benzocyclobutene-fused-cyclooctene, which can be viewed as tCBCO with an additional benzene ring. The study shows that introducing an additional benzene ring favors polymerization and disfavors depolymerization, and the effect is predominantly entropic. The benzo-effect can be leveraged to fine-tune the thermodynamics of polymerization and depolymerization to facilitate the chemical recycling of polymers.

18.
BMC Surg ; 22(1): 353, 2022 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-36192732

RESUMO

BACKGROUND: To explore the effects of nutrition support team (NST) intervention on elderly patients with gastric cancer (GC). METHODS: The elderly GC patients (tumor stage I/II/III), admitted to our department from January 2015 to September 2021, were retrospectively analyzed and divided into NST group and traditional nutrition (TN) group according to nutritional management methods. The immune, inflammatory, nutrition-related indices, postoperative recovery and long-term prognosis of two groups were analyzed. RESULTS: A total of 258 elderly GC patients were included (NST group, n = 125; TN group, n = 133). After propensity score matching (PSM) in ratio of 1:1, 73 pairs of patients were matched. There were statistically significant differences in CD3 and CD4 level postoperative one month and IgG level postoperative one week between NST group and TN group (P < 0.05). There was no significant differences in serum CRP and IL-6 levels preoperative one day, postoperative one week and one month between two groups (P > 0.05). There were significant differences in body mass index (BMI) between the two groups postoperative one month (P < 0.05). The rate of infectious complications in TN group was significantly higher than that in NST group (P < 0.05). There was no statistically significant differences in 3-year relapse-free survival (RFS) or 3-year overall survival (OS) between NST group and TN group (P > 0.05). CONCLUSIONS: Compared with TN management, NST intervention might be benefit to the immune function recovery and nutritional status, but there was no evidence that NST could improve the prognosis of elderly GC patients.


Assuntos
Estado Nutricional , Neoplasias Gástricas , Idoso , Gastrectomia , Humanos , Imunidade , Imunoglobulina G , Interleucina-6 , Recidiva Local de Neoplasia/cirurgia , Apoio Nutricional/métodos , Estudos Retrospectivos , Neoplasias Gástricas/cirurgia
20.
J Dermatolog Treat ; 33(7): 3034-3038, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35892152

RESUMO

BACKGROUND: Vitiligo has a negative effect on children's physical and psychological health. Few studies have examined long-term treatment efficacy for childhood vitiligo. Therefore, we evaluated the long-term effectiveness of non-surgical combination therapy in pediatric patients with vitiligo and analyzed factors that affect its efficacy. METHODS: Pediatric patients (⩽12 years) with vitiligo who were treated with topical corticosteroids/topical calcineurin inhibitors and phototherapy for 12 months were retrospectively studied. Short-term systemic corticosteroids were administered according to individual clinical conditions. All lesions were photographed to assess repigmentation at 3-month intervals. Clinical data, the treatment effectiveness, and factors affecting the therapeutic effect were analyzed. RESULTS: Overall, 110 children (51 [53.6%] girls; mean [SD] age, 7.1 ± 3.0 years; 104 [94.5%] with activity status) were treated for a mean period of 23.13 ± 14.03 months (range, 5-86 months). The overall >50% repigmentation rate was 64.5%. A longer duration of treatment was associated with a higher repigmentation rate (X2 trend = 36.229, P < .001). The vitiligo disease activity score at the first visit was positively correlated with the overall repigmentation rate (rs = 0.301, P = .001). CONCLUSIONS: Treatment lasting longer than 1 year is recommended in children with vitiligo. The best repigmentation effect can be achieved by combination therapy in the rapid progression stage.


Assuntos
Terapia Ultravioleta , Vitiligo , Feminino , Humanos , Criança , Pré-Escolar , Masculino , Vitiligo/tratamento farmacológico , Vitiligo/patologia , Terapia Ultravioleta/efeitos adversos , Estudos Retrospectivos , Resultado do Tratamento , Corticosteroides/uso terapêutico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...