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1.
Nucleic Acids Res ; 51(16): 8550-8562, 2023 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-37395447

RESUMO

In meiosis, Dmc1 recombinase and the general recombinase Rad51 are responsible for pairing homologous chromosomes and exchanging strands. Fission yeast (Schizosaccharomyces pombe) Swi5-Sfr1 and Hop2-Mnd1 stimulate Dmc1-driven recombination, but the stimulation mechanism is unclear. Using single-molecule fluorescence resonance energy transfer (smFRET) and tethered particle motion (TPM) experiments, we showed that Hop2-Mnd1 and Swi5-Sfr1 individually enhance Dmc1 filament assembly on single-stranded DNA (ssDNA) and adding both proteins together allows further stimulation. FRET analysis showed that Hop2-Mnd1 enhances the binding rate of Dmc1 while Swi5-Sfr1 specifically reduces the dissociation rate during the nucleation, about 2-fold. In the presence of Hop2-Mnd1, the nucleation time of Dmc1 filaments shortens, and doubling the ss/double-stranded DNA (ss/dsDNA) junctions of DNA substrates reduces the nucleation times in half. Order of addition experiments confirmed that Hop2-Mnd1 binds on DNA to recruit and stimulate Dmc1 nucleation at the ss/dsDNA junction. Our studies directly support the molecular basis of how Hop2-Mnd1 and Swi5-Sfr1 act on different steps during the Dmc1 filament assembly. DNA binding of these accessory proteins and nucleation preferences of recombinases thus dictate how their regulation can take place.


Assuntos
Rad51 Recombinase , Schizosaccharomyces , Proteínas de Ciclo Celular/metabolismo , DNA/metabolismo , DNA de Cadeia Simples/genética , DNA de Cadeia Simples/metabolismo , Meiose , Rad51 Recombinase/metabolismo , Recombinases/genética , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo
2.
Nucleic Acids Res ; 51(21): 11717-11731, 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-37843130

RESUMO

Fork reversal is a conserved mechanism to prevent stalled replication forks from collapsing. Formation and protection of reversed forks are two crucial steps in ensuring fork integrity and stability. Five RAD51 paralogs, namely, RAD51B, RAD51C, RAD51D, XRCC2 and XRCC3, which share sequence and structural similarity to the recombinase RAD51, play poorly defined mechanistic roles in these processes. Here, using purified BCDX2 (RAD51BCD-XRCC2) and CX3 (RAD51C-XRCC3) complexes and in vitro reconstituted biochemical systems, we mechanistically dissect their functions in forming and protecting reversed forks. We show that both RAD51 paralog complexes lack fork reversal activities. Whereas CX3 exhibits modest fork protection activity, BCDX2 significantly synergizes with RAD51 to protect DNA against attack by the nucleases MRE11 and EXO1. DNA protection is contingent upon the ability of RAD51 to form a functional nucleoprotein filament on DNA. Collectively, our results provide evidence for a hitherto unknown function of RAD51 paralogs in synergizing with RAD51 nucleoprotein filament to prevent degradation of stressed replication forks.


Assuntos
Replicação do DNA , Rad51 Recombinase , Linhagem Celular , Cromossomos/metabolismo , DNA/genética , DNA/metabolismo , Nucleoproteínas/genética , Rad51 Recombinase/genética , Rad51 Recombinase/metabolismo , Humanos
3.
Mol Cancer ; 23(1): 117, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38824567

RESUMO

Significant advancements have been made in the application of chimeric antigen receptor (CAR)-T treatment for blood cancers during the previous ten years. However, its effectiveness in treating solid tumors is still lacking, necessitating the exploration of alternative immunotherapies that can overcome the significant challenges faced by current CAR-T cells. CAR-based immunotherapy against solid tumors shows promise with the emergence of macrophages, which possess robust phagocytic abilities, antigen-presenting functions, and the ability to modify the tumor microenvironment and stimulate adaptive responses. This paper presents a thorough examination of the latest progress in CAR-M therapy, covering both basic scientific studies and clinical trials. This study examines the primary obstacles hindering the realization of the complete potential of CAR-M therapy, as well as the potential strategies that can be employed to overcome these hurdles. With the emergence of revolutionary technologies like in situ genetic modification, synthetic biology techniques, and biomaterial-supported gene transfer, which provide a wider array of resources for manipulating tumor-associated macrophages, we suggest that combining these advanced methods will result in the creation of a new era of CAR-M therapy that demonstrates improved efficacy, safety, and availability.


Assuntos
Imunoterapia Adotiva , Neoplasias , Receptores de Antígenos Quiméricos , Microambiente Tumoral , Humanos , Neoplasias/terapia , Neoplasias/imunologia , Receptores de Antígenos Quiméricos/imunologia , Receptores de Antígenos Quiméricos/genética , Imunoterapia Adotiva/métodos , Microambiente Tumoral/imunologia , Animais , Imunoterapia/métodos
4.
New Phytol ; 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39081031

RESUMO

Chemical-inducible gene expression systems are commonly used to regulate gene expression for functional genomics in various plant species. However, a convenient system that can tightly regulate transgene expression in Nicotiana benthamiana is still lacking. In this study, we developed a tightly regulated copper-inducible system that can control transgene expression and conduct cell death assays in N. benthamiana. We tested several chemical-inducible systems using Agrobacterium-mediated transient expression and found that the copper-inducible system exhibited the least concerns regarding leakiness in N. benthamiana. Although the copper-inducible system can control the expression of some tested reporters, it is not sufficiently tight to regulate certain tested hypersensitive cell death responses. Using the MoClo-based synthetic biology approach, we incorporated the suicide exon HyP5SM/OsL5 and Cre/LoxP as additional regulatory elements to enhance the tightness of the regulation. This new design allowed us to tightly control the hypersensitive cell death induced by several tested leucine-rich repeat-containing proteins and their matching avirulence factors, and it can be easily applied to regulate the expression of other transgenes in transient expression assays. Our findings offer new approaches for both fundamental and translational studies in plant functional genomics.

5.
Lipids Health Dis ; 23(1): 24, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38263010

RESUMO

BACKGROUND: The residual risks of atherosclerotic cardiovascular disease in statin-treated patients with diabetes remain unclear. This study was conducted to identify factors associated with these residual risks in patients with no prior vascular event. METHODS: Data on 683 statin-using patients with type 2 diabetes mellitus (T2DM) from the Taiwan Diabetes Registry were used in this study. Patients aged < 25 or > 65 years at the time of diabetes diagnosis and those with diabetes durations ≥ 20 years were excluded. The United Kingdom Prospective Diabetes Study risk engine (version 2.01; https://www.dtu.ox.ac.uk/riskengine/ ) was used to calculate 10-year residual nonfatal and fatal coronary heart disease (CHD) and stroke risks. Associations of these risks with physical and biochemical variables, including medication use and comorbidity, were examined. RESULTS: The 10-year risks of nonfatal CHD in oral anti-diabetic drug (OAD), insulin and OAD plus insulin groups were 11.8%, 16.0%, and 16.8%, respectively. The 10-year risks of nonfatal stroke in OAD, insulin and OAD plus insulin groups were 3.0%, 3.4%, and 4.3%, respectively. In the multivariate model, chronic kidney disease (CKD), neuropathy, insulin use, calcium-channel blocker (CCB) use, higher body mass indices (BMI), low-density lipoprotein (LDL), fasting glucose, log-triglyceride (TG), and log-alanine transaminase (ALT) levels were associated with an increased CHD risk. The residual risk of stroke was associated with CKD, neuropathy, CCB use, and lower LDL cholesterol levels, higher BMI and diastolic blood pressure. CONCLUSION: This study indicated that insulin was probably a residual risk factor of CHD but not stroke, and that there was a possible presence of obesity paradox in patients with T2DM on statin therapy. In addition to lowering TG and normalizing fasting glucose levels, lower LDL cholesterol level is better for reduction of risk of CHD on statin therapy. On the other hand, lower LDL cholesterol level could potentially be related to higher risk of stroke among populations receiving statin therapy. These findings suggest potential therapeutic targets for residual cardiovascular risk reduction in patients with T2DM on statin therapy.


Assuntos
Diabetes Mellitus Tipo 2 , Inibidores de Hidroximetilglutaril-CoA Redutases , Insuficiência Renal Crônica , Acidente Vascular Cerebral , Humanos , LDL-Colesterol , Estudos Prospectivos , Taiwan , Insulina , Bloqueadores dos Canais de Cálcio , Glucose
6.
Proc Natl Acad Sci U S A ; 118(8)2021 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-33593897

RESUMO

Most eukaryotes possess two RecA-like recombinases (ubiquitous Rad51 and meiosis-specific Dmc1) to promote interhomolog recombination during meiosis. However, some eukaryotes have lost Dmc1. Given that mammalian and yeast Saccharomyces cerevisiae (Sc) Dmc1 have been shown to stabilize recombination intermediates containing mismatches better than Rad51, we used the Pezizomycotina filamentous fungus Trichoderma reesei to address if and how Rad51-only eukaryotes conduct interhomolog recombination in zygotes with high sequence heterogeneity. We applied multidisciplinary approaches (next- and third-generation sequencing technology, genetics, cytology, bioinformatics, biochemistry, and single-molecule biophysics) to show that T. reesei Rad51 (TrRad51) is indispensable for interhomolog recombination during meiosis and, like ScDmc1, TrRad51 possesses better mismatch tolerance than ScRad51 during homologous recombination. Our results also indicate that the ancestral TrRad51 evolved to acquire ScDmc1-like properties by creating multiple structural variations, including via amino acid residues in the L1 and L2 DNA-binding loops.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas Fúngicas/metabolismo , Genoma Fúngico , Recombinação Homóloga , Hypocreales/metabolismo , Meiose , Rad51 Recombinase/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Ciclo Celular/genética , DNA de Cadeia Simples , Proteínas de Ligação a DNA/genética , Proteínas Fúngicas/genética , Hypocreales/genética , Rad51 Recombinase/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética
7.
BMC Med Educ ; 24(1): 349, 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38553678

RESUMO

BACKGROUND: Clinical practicum is crucial for strengthening nursing students' clinical competence. However, nursing students often experience considerable stress during clinical practicum, and so they employ coping strategies to alleviate it. There is almost no empirical evidence on the change trajectory of perceived stress, coping strategies, and clinical competence among nursing students during a one-year clinical practicum. This study aimed to investigate the trajectory of change in perceived stress, coping strategies, and clinical competence among undergraduate nursing students during a one-year clinical practicum. METHODS: This study used a longitudinal cohort design. Undergraduate nursing students were recruited from a science and technology university in Taiwan to participate from February 2021 to January 2022. Perceived stress, coping strategies, and clinical competence among students in basic training practicum (T1), advanced training practicum (T2), and comprehensive clinical nursing practicum (T3) were surveyed by using the Perceived Stress Scale (PSS), Coping Behaviour Inventory (CBI), and Clinical Competence Scale (CCS). PSS, CBI, and CCS in T1, T2, and T3 were compared using a generalized estimating equation (GEE) to deal with correlated data. The level of statistical significance was set at α = 0.05. RESULTS: A total of 315 undergraduate nursing students completed the questionnaire. The study results show that the overall perceived stress of the students is the highest in T2 and the lowest in T3. The main source of stress of the students is 'taking care of patients' at T1 and 'lack of professional knowledge and skills' at T2 and T3. Students' perceived stress in 'taking care of patients' gradually decreases over time. The four coping strategies of CBI, which are 'stay optimistic', 'problem-solving', 'transference' and 'avoidance' in this order, remain the same ranking in three surveys.The main stress coping strategy used by students is 'stay optimistic', while the coping strategy 'avoidance' is used more frequently in T2 than in T1 and T3. Students' mean scores of the overall clinical competence and in the 'general nursing' and 'management' subscales in T3 are higher than those in T1 and T2. However, their mean scores in 'self-growth' and 'positivity' subscales are the highest in T1 and the lowest in T2. CONCLUSIONS: The results show that through experiential learning in clinical practicum at different stages time after time, students' overall perceived stress is the lowest and their overall clinical competence is the highest in T3. The main coping strategy used when students managed stress is 'stay optimistic'. According to the results, we suggest that clinical educators provide students with appropriate guidance strategies at different stages of stress and continue to follow up the clinical competence and retention rates of these nursing students in the workplace in the future.


Assuntos
Bacharelado em Enfermagem , Testes Psicológicos , Autorrelato , Estudantes de Enfermagem , Humanos , Capacidades de Enfrentamento , Estudos Longitudinais , Bacharelado em Enfermagem/métodos , Competência Clínica , Preceptoria , Estresse Psicológico
8.
J Formos Med Assoc ; 123(3): 325-330, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38097427

RESUMO

AIMS: Advanced maternal age (AMA) is correlated with higher risk of adverse pregnancy outcomes while the pathophysiology remains unclear. Our study aimed to investigate whether AMA is linked to the clustering of metabolic abnormalities, which in turn is associated with an increased risk of adverse pregnancy outcomes. METHOD: A total of 857 pregnant woman were recruited in a prospective cohort at National Taiwan University Hospital, from November 2013 to April 2018. Metabolic abnormalities during pregnancy were defined as following: fasting plasma glucose ≥92 mg/dl, body mass index (BMI) ≥24 kg/m2, plasma high-density lipoprotein cholesterol <50 mg/dl, hyper-triglyceridemia (≥140 mg/dl in the first trimester or ≥220 mg/dl in the second trimester), and blood pressure ≥130/85 mmHg. RESULT: Incidence of large for gestational age (LGA), primary caesarean section (CS), and the presence of any adverse pregnancy outcome increased with age. The advanced-age group tended to have more metabolic abnormalities in both the first and the second trimesters. There was a significant association between the number of metabolic abnormalities in the first and the second trimesters and the incidence of LGA, gestational hypertension or preeclampsia, primary CS, preterm birth, and the presence of any adverse pregnancy outcome, adjusted for maternal age. CONCLUSION: AMA is associated with clustering of metabolic abnormalities during pregnancy, and clustering of metabolic abnormalities is correlated with increased risk of adverse pregnancy outcomes.


Assuntos
Resultado da Gravidez , Nascimento Prematuro , Gravidez , Recém-Nascido , Humanos , Feminino , Resultado da Gravidez/epidemiologia , Estudos Prospectivos , Idade Materna , Cesárea , Nascimento Prematuro/epidemiologia
9.
Sensors (Basel) ; 24(5)2024 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-38475020

RESUMO

A detection and classification machine-learning model to inspect Thin Film Transistor Liquid Crystal Display (TFT-LCD) Mura is proposed in this study. To improve the capability of the machine-learning model to inspect panels' low-contrast grayscale images, piecewise gamma correction and a Selective Search algorithm are applied to detect and optimize the feature regions based on the Semiconductor Equipment and Materials International Mura (SEMU) specifications. In this process, matching the segment proportions to gamma values of piecewise gamma is a task that involves derivative-free optimization which is trained by adaptive particle swarm optimization. The detection accuracy rate (DAR) is approximately 93.75%. An enhanced convolutional neural network model is then applied to classify the Mura type through using the Taguchi experimental design method that identifies the optimal combination of the convolution kernel and the maximum pooling kernel sizes. A remarkable defect classification accuracy rate (CAR) of approximately 96.67% is ultimately achieved. The entire defect detection and classification process can be completed in about 3 milliseconds.

10.
BMC Nurs ; 23(1): 227, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38566058

RESUMO

BACKGROUND: Some studies suggest that female patients have more concerns about receiving intimate care from male than female nurses. Thus, providing intimate care to female patients is a challenging experience for male nurses. The purpose of this study was to explore Chinese male nurses' experiences and process of providing intimate clinical care to female patients. METHODS: A constructivist grounded theory approach was used to develop a theoretical understanding of male nurses' experiences. This study included participants from 3 hospitals in different locations in China. Twenty-five male nurses were recruited using purposive and theoretical sampling. Semi-structured interviews were conducted. Data analysis was completed using initial coding, focused coding, theoretical coding and memo writing to produce core concepts and categories, and theory development. RESULTS: Chinese male nurses' experiences of providing intimate care to female patients can be constructed as a three-stage process: (1) anticipation of the level of embarrassment, (2) deciding on the process: do it or not do it and (3) protecting both parties and dealing with embarrassment. Additionally, seven themes and associated categories were identified to represent the important factors in the process of male nurses providing intimate care to female patients in China. CONCLUSIONS: Chinese traditional culture may affect the embarrassment in Chinese male nurses providing intimate care to female patients. The embarrassing situation can be divided into three different stages, and male nurses have different main concerns in each stage. Hospital nursing administrators should consider the experiences and needs of male nurses in providing intimate care and provide them with psychological support, education and training.

11.
BMC Nurs ; 23(1): 58, 2024 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-38245735

RESUMO

BACKGROUND: A high percentage of cancer patients may experience emotional distress. Oncology nurses are expected to play an important role in recognizing emotional distress and planning and delivering care that meets the individual needs of each patient. However, few studies have focused on the experiences of clinical nurses in such cases. This study adopted a qualitative research method to gain an in-depth understanding of the experience of nursing staff in caring for cancer patients with emotional distress. METHODS: A qualitative descriptive design and semi-structured interviews were used in this study. Twenty-one oncology nurses were interviewed, and the qualitative content analysis suggested by Graneheim & Lundman (2004) was used to interpret the data. RESULTS: Six themes were identified, as follows: (1) dictating the abnormality of emotion, (2) soothing and comforting patients, (3) a lack of psychology knowledge and communication skills, (4) negative impacts of a lack of time, (5) managing emotional labor, and (6) reflecting on the experiences. CONCLUSION: Hospital administrators should arrange pre-employment education and training as well as on-the-job education to help nurses in caring for cancer patients with emotional distress. They should also focus attention on the personal emotional states of nursing staff in a timely manner and provide psychological support and emotional counseling as necessary.

12.
Chemistry ; 29(57): e202301379, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37434348

RESUMO

A strategy that combines electrochemical synthesis and photoredox catalysis was reported for the efficient synthesis of imines. This approach was demonstrated to be highly versatile in producing various types of imines, including symmetric and unsymmetric imines, by exploring the impact of different substituents on the benzene ring of the arylamine. Additionally, the method was specifically applied to modify N-terminal phenylalanine residues and was found to be successful in the photoelectrochemical cross-coupling reaction between NH2 -Phe-OMe and aryl methylamines, leading to the synthesis of phenylalanine-containing imines. Therefore, this technique would present a convenient and efficient platform for synthesizing imines, with promising applications in chemical biology, drug development, and organic synthesis.

13.
Clin Sci (Lond) ; 137(1): 17-30, 2023 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-36416117

RESUMO

Oxidative stress is vital for pathophysiology of atherosclerosis and non-alcoholic fatty liver disease (NAFLD). Monoamine oxidase (MAO) is an important source of oxidative stress in the vascular system and liver. However, the effect of MAO inhibition on atherosclerosis and NAFLD has not been explored. In the present study, MAO A and B expressions were increased in atherosclerotic plaques in human and apolipoprotein E (ApoE)-deficient mice. Inhibition of MAO B (by deprenyl), but not MAO A (by clorgyline), reduced the atheroma area in the thoracic aorta and aortic sinus in ApoE-deficient mice fed the cholesterol-enriched diet for 15 weeks. MAO B inhibition attenuated oxidative stress, expression of adhesion molecules, production of inflammatory cytokines, and macrophage infiltration in atherosclerotic plaques and decreased plasma triglyceride and low-density lipoprotein (LDL) cholesterol concentrations. MAO B inhibition had no therapeutic effect on restenosis in the femoral artery wire-induced injury model in C57BL/6 mice. In the NAFLD mouse model, MAO B inhibition reduced lipid droplet deposition in the liver and hepatic total cholesterol and triglyceride levels in C57BL/6 mice fed high-fat diets for 10 weeks. Key enzymes for triglyceride and cholesterol biosynthesis (fatty acid synthase and 3-hydroxy-3-methylglutaryl-CoA reductase, HMGCR) and inflammatory markers were inhibited, and cholesterol clearance was up-regulated (increased LDL receptor expression and reduced proprotein convertase subtilisin/kexin type 9, PCSK9, expression) by MAO B inhibition in the liver. These results were also demonstrated in the HepG2 liver cell model. Our data suggest that MAO B inhibition is a potential and novel treatment for atherosclerosis and NAFLD.


Assuntos
Aterosclerose , Hipercolesterolemia , Hepatopatia Gordurosa não Alcoólica , Placa Aterosclerótica , Camundongos , Humanos , Animais , Placa Aterosclerótica/metabolismo , Pró-Proteína Convertase 9/metabolismo , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/metabolismo , Monoaminoxidase/metabolismo , Camundongos Endogâmicos C57BL , Aterosclerose/tratamento farmacológico , Aterosclerose/prevenção & controle , Colesterol/metabolismo , Fígado/metabolismo , Triglicerídeos/metabolismo , Hipercolesterolemia/metabolismo , Apolipoproteínas E
14.
Am J Obstet Gynecol ; 2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-38036165

RESUMO

BACKGROUND: Whether myomectomy increases the risk of placenta accreta spectrum in the following pregnancies remains controversial. OBJECTIVE: This study aimed to investigate the effect of myomectomy on the risk of placenta accreta spectrum in the following pregnancies. Moreover, different methods of myomectomy on the risk of placenta accreta spectrum were explored. STUDY DESIGN: A nationwide cohort study was conducted using data from the Taiwan National Health Insurance Research Database, including all pregnant patients in Taiwan who gave birth between January 2008 and December 2017. A 1:1 propensity score estimation matching was performed for the analysis of myomectomy on the risk of placenta accreta spectrum. Among pregnant patients who received myomectomy, different methods of myomectomy on the risk of placenta accreta spectrum were compared with the control group. RESULTS: Among the 1,371,458 pregnant patients in this study, 11,255 pregnant patients had a history of myomectomy. The risk of placenta accreta spectrum was higher in pregnant patients with a history of myomectomy than in pregnant patients without a history of myomectomy (incidence: 0.96% vs 0.20%; adjusted odds ratio, 2.28; 95% confidence interval, 1.85-2.81; P<.01). Among pregnant patients with a history of myomectomy, 5045 (46.87%) received laparotomic myomectomy, 3973 (36.93%) received laparoscopic myomectomy, and 1742 (16.20%) received hysteroscopic myomectomy. The incidence of placenta accreta spectrum was higher in the hysteroscopic group than in the laparotomic group or the laparoscopic group (1.89% [hysteroscopic group] vs 0.71% [laparotomic group] and 0.81% [laparoscopic group]; P<.05). Compared with patients without a history of myomectomy, the adjusted odds ratio for placenta accreta spectrum was 3.88 (95% confidence interval, 2.68-5.63; P<.05) in the hysteroscopic group. CONCLUSION: Myomectomy, especially hysteroscopic myomectomy, is associated with an increased risk of placenta accreta spectrum in the subsequent pregnancy.

15.
Nanotechnology ; 34(25)2023 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-36944230

RESUMO

Two-dimensional (2D) materials and their heterostructures exhibit intriguing optoelectronic properties; thus, they are good platforms for exploring fundamental research and further facilitating real device applications. The key is to preserve the high quality and intrinsic properties of 2D materials and their heterojunction interface even in production scale during the transfer and assembly process so as to apply in semiconductor manufacturing field. In this study, we successfully adopted a wet transfer existing method to separate mediator-assisted wafer-scale from SiO2/Si growing wafer for the first time with intermediate annealing to fabricate wafer-scale MoS2/h-BN and WS2/h-BN heterostructures on a SiO2/Si wafer. Interestingly, the high-quality wafer-scale 2D material heterostructure optical properties were enhanced and confirmed by Raman and photoluminescence spectroscopy. Our approach can be applied to other 2D materials and expedite mass production for industrial applications.

16.
Proc Natl Acad Sci U S A ; 117(21): 11257-11264, 2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-32404423

RESUMO

Dmc1 recombinases are essential to homologous recombination in meiosis. Here, we studied the kinetics of the nucleoprotein filament assembly of Saccharomyces cerevisiae Dmc1 using single-molecule tethered particle motion experiments and in vitro biochemical assay. ScDmc1 nucleoprotein filaments are less stable than the ScRad51 ones because of the kinetically much reduced nucleation step. The lower nucleation rate of ScDmc1 results from its lower single-stranded DNA (ssDNA) affinity, compared to that of ScRad51. Surprisingly, ScDmc1 nucleates mostly on the DNA structure containing the single-stranded and duplex DNA junction with the allowed extension in the 5'-to-3' polarity, while ScRad51 nucleation depends strongly on ssDNA lengths. This nucleation preference is also conserved for mammalian RAD51 and DMC1. In addition, ScDmc1 nucleation can be stimulated by short ScRad51 patches, but not by EcRecA ones. Pull-down experiments also confirm the physical interactions of ScDmc1 with ScRad51 in solution, but not with EcRecA. Our results are consistent with a model that Dmc1 nucleation can be facilitated by a structural component (such as DNA junction and protein-protein interaction) and DNA polarity. They provide direct evidence of how Rad51 is required for meiotic recombination and highlight a regulation strategy in Dmc1 nucleoprotein filament assembly.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas de Ligação a DNA/metabolismo , Meiose , Rad51 Recombinase/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Ciclo Celular/genética , Citoesqueleto/metabolismo , DNA de Cadeia Simples/metabolismo , Proteínas de Ligação a DNA/genética , Nucleoproteínas/metabolismo , Rad51 Recombinase/genética , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Imagem Individual de Molécula/métodos
17.
Hu Li Za Zhi ; 70(5): 36-43, 2023 Oct.
Artigo em Zh | MEDLINE | ID: mdl-37740263

RESUMO

BACKGROUND: The multiple symptoms of Sjögren's syndrome lead patients affected by this disease to seek medical advice from different medical disciplines and specialists. Diagnoses are often made many years after initial onset, resulting in mental and physical exhaustion and misunderstandings. PURPOSE: This study was designed to explore the health-seeking experiences of patients with Sjögren's syndrome. METHODS: Qualitative research methods and purposive sampling were used. Fourteen patients with Sjögren's syndrome were interviewed by the first author, and the collected data were analyzed using content analysis. RESULTS: Four themes were revealed from the data, including: (1) distressing symptoms; (2) difficulty in diagnosis; (3) concerns about drug side effects; and (4) facing the disease. The participants initially sought medical attention when they began experiencing early onset symptoms that caused discomfort or annoyance. Their doctors' failure to provide proper diagnoses during the long health-seeking process caused a great deal of suffering to the participants. Although related medications should be taken for life, the participants reported taking lower-than-prescribed dosages out of fear of side-effects. The participants explored their process of coping with the disease, which began with denial and ended with acceptance. By learning from their health-seeking process, participants realized that they needed to take proper care of themselves, adapt to life with their disease, and control related symptoms. CONCLUSIONS / IMPLICATIONS FOR PRACTICE: To facilitate the early diagnosis of Sjögren's syndrome, healthcare professionals should improve their awareness of this condition and refer patients with related symptoms to rheumatologists and immunologists. Effective early diagnosis and treatment can help these patients reduce the time and effort involved in unproductive doctor's visits, allowing them to better continue as productive members of society and to maintain a good quality of life.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Síndrome de Sjogren , Humanos , Qualidade de Vida , Síndrome de Sjogren/diagnóstico , Adaptação Psicológica , Fadiga
18.
Small ; 18(32): e2201779, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35835723

RESUMO

Current circulating tumor cells (CTCs) detection strategies based on surface epithelial markers suffer from low specificity in distinguishing between CTCs and epithelial cells in hematopoietic cell population. Tumor-associated miRNAs within CTCs are emerging as new biomarkers due to their high correlation with tumor development and progress. However, in-situ simultaneous analysis of multiple miRNAs in single CTC cell is still challenging. To overcome this limitation, a digital droplet microfluidic flow cytometry based on biofunctionalized 2D metal-organic framework nanosensor (Nano-DMFC) is developed for in situ detection of dual miRNAs simultaneously in single living breast cancer cells. Here, 2D MOF-based fluorescent resonance energy transfer (FRET) nanosensors are established by conjugating dual-color fluorescence dye-labeled DNA probes on MOF nanosheet surface. In the Nano-DMFC, 2D MOF-based nanoprobes are precisely microinjected into each single-cell encapsulated droplets to achieve dual miRNA characterization in single cancer cell. This Nano-DMFC platform successfully detects dual miRNAs at single-cell resolution in 10 mixed positive MCF-7 cells out of 10 000 negative epithelial cells in serum biomimic samples. Moreover, this Nano-DMFC platform shows good reproductivity in the recovery experiment of spiked blood samples, which demonstrate the high potential for CTC-based cancer early diagnosis and prognosis.


Assuntos
MicroRNAs , Células Neoplásicas Circulantes , Biomarcadores Tumorais , Linhagem Celular Tumoral , Citometria de Fluxo , Humanos , Células MCF-7 , Microfluídica , Células Neoplásicas Circulantes/patologia
19.
Nucleic Acids Res ; 48(16): 9135-9146, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32735676

RESUMO

Microcephalin 1 (MCPH1) was identified from genetic mutations in patients with primary autosomal recessive microcephaly. In response to DNA double-strand breaks (DSBs), MCPH1 forms damage-induced foci and recruits BRCA2-RAD51 complex, a key component of the DSB repair machinery for homologous recombination (HR), to damage sites. Accordingly, the efficiency of HR is significantly attenuated upon depletion of MCPH1. The biochemical characteristics of MCPH1 and its functional interaction with the HR machinery had remained unclear due to lack of highly purified MCPH1 recombinant protein for functional study. Here, we established a mammalian expression system to express and purify MCPH1 protein. We show that MCPH1 is a bona fide DNA-binding protein and provide direct biochemical analysis of this MCPH family protein. Furthermore, we reveal that MCPH1 directly interacts with RAD51 at multiple contact points, providing evidence for how MCPH1 physically engages with the HR machinery. Importantly, we demonstrate that MCPH1 enhances the stability of RAD51 on single-strand DNA, a prerequisite step for RAD51-mediated recombination. Single-molecule tethered particle motion analysis showed a ∼2-fold increase in the lifetime of RAD51-ssDNA filaments in the presence of MCPH1. Thus, our study demonstrates direct crosstalk between microcephaly protein MCPH1 and the recombination component RAD51 for DSB repair.


Assuntos
Proteína BRCA2/genética , Proteínas de Ciclo Celular/genética , Proteínas do Citoesqueleto/genética , Microcefalia/genética , Rad51 Recombinase/genética , Citoesqueleto/genética , Quebras de DNA de Cadeia Dupla , Dano ao DNA/genética , Reparo do DNA/genética , DNA de Cadeia Simples/genética , Proteínas de Ligação a DNA/genética , Instabilidade Genômica/genética , Recombinação Homóloga/genética , Humanos , Microcefalia/patologia , Nucleoproteínas/genética
20.
J Formos Med Assoc ; 121(1 Pt 1): 193-201, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33766449

RESUMO

BACKGROUND/PURPOSE: Hypertension is a risk factor of incident diabetes. In 2017, the ACC/AHA updated the definition of hypertension to above 130/80 mmHg, while the 2018 ESC/ESH guideline and the JNC7 criteria remained the cutoff of 140/90 mmHg. This study was aimed to investigate how different cutoffs of hypertension affect the association of hypertension to incident diabetes and the progression of insulin resistance. METHODS: A total of 1177 subjects without diabetes at baseline were followed for 4.5 years. Diabetes was diagnosed by the results of oral glucose tolerance tests and hemoglobin A1c, or if anti-diabetic agents were used. RESULTS: Hypertension by both criteria was associated with incident diabetes. Change of HOMA2-IR every 5 years (ΔHOMA2-IR/5 yr) was higher in subjects with hypertension than those without (adjusted p = 0.044). Subjects with treated hypertension had the highest risk of diabetes (HR 2.98, p < 0.001) and ΔHOMA2-IR/5 yr, compared with subjects with normal blood pressure. However, the associations of hypertension, HR of incident diabetes and ΔHOMA2-IR/5 yr were attenuated by the 2017 ACC/AHA criteria, as compared with that by the JNC7 and 2018 ESC/ESH criteria. CONCLUSION: Hypertension by both criteria is associated with incident diabetes and accelerated progression of insulin resistance, and the associations are attenuated by the 2017 ACC/AHA criteria.


Assuntos
Diabetes Mellitus , Hipertensão , Resistência à Insulina , Diabetes Mellitus/epidemiologia , Humanos , Hipertensão/epidemiologia , Estudos Prospectivos
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