Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
1.
Int J Surg ; 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38759694

RESUMO

BACKGROUND: Testicular cancer (TC) is currently the most common malignancy in young and middle-aged men. A comprehensive assessment of TC burden is in lack. METHOD: Global incidence, deaths, and disability-adjusted life-years (DALYs) of TC from 1990 to 2019 were obtained. Estimated annual percentage change (EAPC) was calculated to quantify trends in TC changes during the period. Relationships between disease burden and age, sociodemographic index (SDI) levels, human development index (HDI) were further analyzed. RESULTS: Globally, incident cases of TC more than doubled from 1990 to 2019, together with an increasing of global age-standardized incidence rates (ASIR) of TC from 1.9 to 2.8. The age-standardized deaths rates (ASDR) remained stable from 0.31 to 0.28. The similar results were reflected in the disability-adjusted life-years (DALYs). In 2019, the highest ASIR were found in Southern Latin America, Central Europe and Western Europe. Analogously, the highest ASDR were found in Southern Latin America followed by Central Latin America and Central Europe. The burden of incidence increased with SDI, appropriately reached a peak at about 0.78, and then declined. Similarly, the burden of deaths increased with SDI, met a maximum at about 0.7. CONCLUSIONS: From 1990 to 2019, the ASIR of TC has increased significantly, while the ASDR has been relatively stable and slightly decreased. The disease burden of TC is shifting to regions and countries with moderate to high levels of development. TC remains a rapidly growing global health problem, and new changes in TC burden should be considered when formulating new TC control policies.

2.
Micromachines (Basel) ; 14(9)2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37763865

RESUMO

In this work, we demonstrated a kind of flexibly monolithic saturable absorber (SA) with GaAs nanowires (NWs) on polyimide (PI) plastic substrate for broadband optical modulation at 1.0 and 1.5 µm, separately. The monolithic SA sample was prepared by the metalorganic vapor phase epitaxy (MOVPE) method. The crystal structure and element analysis were examined carefully by high-resolution scanning transmission electron microscopy (HRSTEM) and energy-dispersive X-ray spectroscopy (EDX). We observed a high-density distribution of NWs on the flexible substrate by scanning electron microscopy (SEM). In addition, linear and nonlinear optical properties of the sample were examined by testing the photoluminescence and absorption properties, which showed its potential application as an optical switch due to the pure semiconducting properties. After the characterizations, we experimentally demonstrated this monolithic SA for laser modulation at 1.0 and 1.5 µm, which yielded the minimum optical pulse widths of 1.531 and 6.232 µs, respectively. Our work demonstrated such a kind of monolithic flexible NW substrate-integrated device used for broadband optical modulation, which not only eased the integration process of NWs onto the fiber endface, but also proved the potential of easily integrating with more semiconducting nanomaterials (e.g., graphene, MoS2, …) to realize monolithic active flexible photonic systems, such as a microscale phase modulator, delay-line, and so on, paving an easy avenue for the development of both active and flexible photonic devices.

3.
Micromachines (Basel) ; 14(6)2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-37374783

RESUMO

We systematically studied several of the most traditional hollow-core anti-resonant fiber (HC-ARF) structures, with the aim of achieving low confinement loss, single-mode performance, and high insensitivity to bending in the 2 µm band. Moreover, the propagation loss of fundamental mode (FM), higher-order mode (HOMs), and the higher-order mode extinction ratio (HOMER) under different geometric parameters were studied. Analysis showed that the confinement loss of the six-tube nodeless hollow-core anti-resonant fiber at 2 µm was 0.042 dB/km, and its higher-order mode extinction ratio was higher than 9000. At the same time, a confinement loss of 0.040 dB/km at 2 µm was achieved in the five-tube nodeless hollow-core anti-resonant fiber, and its higher-order mode extinction ratio was higher than 2700.

4.
BMC Med Educ ; 23(1): 219, 2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-37024905

RESUMO

BACKGROUND: After the COVID-19 epidemic, the state has paid more attention to the clinical teaching function of affiliated hospitals of colleges and universities. Strengthening the integration of medicine and education and improving the quality and effect of clinical practice teaching are critical challenges facing medical education. The difficulty of orthopedic teaching lies in the characteristics of a wide variety of diseases, strong professionalism, and relatively abstract characteristics, which affect the initiative, enthusiasm, and learning effect of nursing students. In this study, a flipped classroom teaching plan based on the CDIO (conceive-design-implement-operate) concept was constructed and practiced in the orthopedic nursing student training course to improve the effect of practical teaching, and it is convenient for teachers to implement more effective and targeted teaching in the flipped classroom of nursing education and even medical education in the future. METHODS: Fifty undergraduate nursing students who practiced in the Orthopedics Department of a tertiary hospital in June 2017 were enrolled in the control group, while 50 undergraduate nursing students who practiced in the same department in June 2018 were enrolled in the intervention group. The intervention group adopted the flipped classroom teaching mode of the CDIO concept, whereas the control group adopted the traditional teaching mode. After finishing the department practice task, the students in the two groups completed the evaluation of theory, operation skills, independent learning ability, and critical thinking ability. They completed the evaluation of clinical practice ability in eight dimensions, including four processes of nursing procedures, humanistic care ability, and evaluation of clinical teaching quality for two groups of teachers. RESULTS: After teaching, the clinical practice ability, critical thinking ability, autonomous learning ability, theoretical and operational performance, and evaluation of clinical teaching quality in the intervention group were significantly higher than those in the control group (all p < 0.05). CONCLUSION: The CDIO-based teaching mode can stimulate the independent learning ability and critical thinking ability of nursing interns, promote the organic combination of theory and practice, improve their ability to comprehensively use theoretical knowledge to analyze and solve practical problems, and improve teaching effectiveness.


Assuntos
COVID-19 , Bacharelado em Enfermagem , Estudantes de Enfermagem , Humanos , Bacharelado em Enfermagem/métodos , Enfermagem Ortopédica , Aprendizagem , Aprendizagem Baseada em Problemas/métodos , Ensino , Currículo
5.
Methods Enzymol ; 680: 139-162, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36710009

RESUMO

Protein cross-linking is the process of chemically joining two amino acids in a protein or protein complex by a covalent bond. When combined with mass spectrometry, it becomes one of the structural mass spectrometry techniques gaining in importance for deriving valuable three-dimensional structural information on proteins and protein complexes. This platform complements existing structural methods, such as NMR spectroscopy, X-ray crystallography, and cryo-EM. Photosynthetic pigment protein complexes serve as light-energy harvesting systems and perform photochemical conversion as part of the "early events" of photosynthesis. This chapter outlines how to prepare cross-linking pigment protein complex samples for LC-MS/MS analysis, including identification of the cross-linked species, network analysis in a protein complex, and structural modeling and justification.


Assuntos
Proteínas , Espectrometria de Massas em Tandem , Cromatografia Líquida , Proteínas/química , Fotossíntese , Aminoácidos , Reagentes de Ligações Cruzadas/química
6.
Biochim Biophys Acta Bioenerg ; 1864(2): 148955, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36708912

RESUMO

Cyanobacteria inhabiting desert biological soil crusts face the harsh conditions of the desert. They evolved a suite of strategies toward desiccation-hydration cycles mixed with high light irradiations, etc. In this study we purified and characterized the structure and function of Photosystem I (PSI) from Leptolyngbya ohadii, a desiccation-tolerant desert cyanobacterium. We discovered that PSI forms tetrameric (PSI-Tet) aggregate. We investigated it by using sucrose density gradient centrifugation, clear native PAGE, high performance liquid chromatography, mass spectrometry (MS), time-resolved fluorescence (TRF) and time-resolved transient absorption (TA) spectroscopy. MS analysis identified the presence of two PsaB and two PsaL proteins in PSI-Tet and uniquely revealed that PsaLs are N-terminally acetylated in contrast to non-modified PsaL in the trimeric PSI from Synechocystis sp. PCC 6803. Chlorophyll (Chl) a fluorescence decay profiles of the PSI-Tet performed at 77 K revealed two emission bands at ∼690 nm and 725 nm with the former appearing only at early delay time. The main fluorescence emission peak, associated with emission from the low energy Chls a, decays within a few nanoseconds. TA studies demonstrated that the 725 nm emission band is associated with low energy Chls a with absorption band clearly resolved at ∼710 nm at 77 K. In summary, our work suggests that the heterogenous composition of PsaBs and PsaL in PSI-Tet is related with the adaptation mechanisms needed to cope with stressful conditions under which this bacterium naturally grows.


Assuntos
Complexo de Proteína do Fotossistema I , Synechocystis , Complexo de Proteína do Fotossistema I/metabolismo , Dessecação , Análise Espectral , Synechocystis/metabolismo , Espectrometria de Massas
7.
Photosynth Res ; 154(2): 113-124, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36070061

RESUMO

Light-harvesting antennas in photosynthesis capture light energy and transfer it to the reaction centers (RCs) where photochemistry takes place. The sustainable growth of the reef-building corals relies on a constant supply of the photosynthates produced by the endosymbiotic dinoflagellate, belonging to the family of Symbiodiniaceae. The antenna system in this group consists of the water-soluble peridinin-chlorophyll a-protein (PCP) and the intrinsic membrane chlorophyll a-chlorophyll c2-peridinin protein complex (acpPC). In this report, a nonameric acpPC is reported in a dinoflagellate, Fugasium kawagutii (formerly Symbiodinium kawagutii sp. CS-156). We found that extensive biochemical purification altered the oligomerization states of the initially isolated nonameric acpPC. The excitation energy transfer pathways in the acpPC nonamer and its variants were studied using time-resolved fluorescence and time-resolved absorption spectroscopic techniques at 77 K. Compared to the well-characterized trimeric acpPC, the nonameric acpPC contains an 11 nm red-shifted terminal energy emitter and substantially altered excited state lifetimes of Chl a. The observed energetic overlap of the fluorescence terminal energy emitters with the absorption of RCs is hypothesized to enable efficient downhill excitation energy transfer. Additionally, the shortened Chl a fluorescence decay lifetime in the oligomeric acpPC indicate a protective self-relaxation strategy. We propose that the highly-oligomerized acpPC nonamer represents an intact functional unit in the Symbiodiniaceae thylakoid membrane. They perform efficient excitation energy transfer (to RCs), and are under manageable regulations in favor of photoprotection.


Assuntos
Antozoários , Dinoflagellida , Animais , Antozoários/metabolismo , Clorofila A/metabolismo , Complexos de Proteínas Captadores de Luz/metabolismo , Dinoflagellida/metabolismo , Clorofila/metabolismo
8.
J Photochem Photobiol B ; 230: 112438, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35405617

RESUMO

Proper rheological properties of red blood cells (RBC) including flexibility and aggregability are essential for healthy blood microcirculation. Excessive RBC aggregation has been observed to be associated with many pathological conditions and is crucial in acute circulatory problems. Low-level laser radiation (LLLR) has been found to have positive effects on the rheology of human blood, however, the detailed mechanisms of blood photobiomodulation remains unclear. In this study, utilizing the single-cell technique optical tweezers (OT) and traditional light microscopy, the influence of photobiomodulation of human RBC was examined under different conditions of laser irradiation. The results revealed that high radiant exposure (over 170.5 J/cm2 radiant fluence) caused enhanced RBC aggregation and cell shape transformation while the aggregation force between single RBC remained unchanged. LLLR with radiant fluence below 9.5 J/cm2 by 450 nm wavelength improved the RBC deformability, weakened the strength of cell-cell interaction in the RBC disaggregation process, and showed rejuvenating effects on RBC suspended in a harsh cell environment.


Assuntos
Agregação Eritrocítica , Deformação Eritrocítica , Eritrócitos , Humanos , Lasers , Reologia
9.
Appl Opt ; 59(6): 1741-1745, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32225681

RESUMO

A self-made saturable absorber (SA) based on hybridized graphene oxide (GO) and ${{\rm Fe}_{3}}{{\rm O}_{4}}$Fe3O4 nanoparticles (FONP) was inserted into a linear cavity to generate a passively $ Q $Q-switched solid-state ${\rm Nd}\text:{{\rm YVO}_4}$Nd:YVO4 laser operating at the 1.3 µm waveband. The laser had a minimum pulse width of 163 ns and a maximum repetition rate of 314 kHz. This experiment, to the best of our knowledge, is the first to demonstrate that hybridized GO and FONP (GO-FONP) can be used as an SA in passively $ Q $Q-switched pulse lasers. Results show that GO-FONP has the potential to be used for passively $ Q $Q-switched laser generation.

10.
Opt Express ; 27(18): 24945-24952, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31510375

RESUMO

An ultrafast coherent long wavelength MIR source based on difference frequency generation was demonstrated. An average power of 2.5 mW at ∼18 µm was achieved. The angular distribution of the generated MIR source under the condition of tight-focusing limit shows the onset of conical emission of the MIR beam due to on-axis phase mismatching.

11.
Gene ; 665: 201-207, 2018 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-29729380

RESUMO

This study firstly used a rat traumatic brain injury model to compare the therapeutic effects of different intravenous infusion speed of 7.5% hypertonic saline (HS). Then the authors applied different delivery rate of 7.5% HS to two groups of patients to figure out the optimal infusion rates. A total of 100 rats were randomly divided into control group, group A (7.5% HS 6 mL/h), group B (7.5% HS 3 mL/h), and group C (7.5% HS 2 mL/h). All rats were established for the brain injury model. A total of 30 patients were selected and randomly divided into group A (250 mL/h) and group B (125 mL/h), with 15 cases in each group. Urine amount was recorded per hour; furthermore, blood was extracted from the patients to measure the levels of AQP4, NKCC1, tumour necrosis factor-α (TNF-a), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6). Compared with other groups, the expression levels of NKCC1 and AQP4 mRNA in group A was the lowest (P < 0.05). NKCC1 and AQP4 protein expression levels were the lowest in all the groups (P < 0.05). On the aspect of patients, group A displayed more significant difference compared with B group in terms of AQP4, NKCC1, TNF-a, IL-1ß, and IL-6 (P < 0.05). In the two groups, a significant difference was noted in the urine amount at 4 h after administration (P < 0.05). In our study, infusion of hypertonic saline (250 mL/h) at the optimal rate of 7.5% HS decreased the intracranial pressure, brain tissue edema, and inflammatory cytokine expression; moreover, it can promote brain tissue protection.


Assuntos
Edema Encefálico , Lesões Encefálicas Traumáticas , Animais , Aquaporina 4/biossíntese , Edema Encefálico/tratamento farmacológico , Edema Encefálico/metabolismo , Edema Encefálico/patologia , Lesões Encefálicas Traumáticas/tratamento farmacológico , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/patologia , Citocinas/biossíntese , Modelos Animais de Doenças , Pressão Intracraniana/efeitos dos fármacos , Masculino , Ratos , Ratos Sprague-Dawley , Solução Salina Hipertônica , Membro 2 da Família 12 de Carreador de Soluto/biossíntese
12.
Appl Opt ; 55(29): 8271-8275, 2016 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-27828073

RESUMO

A "cleaving-polishing" process for end-face treatment of specialty fiber supported by thick-walled silica glass tubes is proposed. The fiber tension is determined by the fiber fracture theory for improved cleaving. This method overcomes polishing problems caused by steel or ceramic ferrules. Approximately 20 min on average is required for polishing a specialty fiber end face with a sampling roughness of 7.42 nm, confirmed by microscopy (400×) and interferometry. A comparison of laser coupling efficiencies between fibers with cleaved ends and fibers with polished ends showed that the coupling efficiency of the former could be enhanced by 15% through polishing.

13.
Biomed Rep ; 4(3): 379-383, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26998280

RESUMO

A migraine is a disabling neurovascular disorder characterized by a unilateral throbbing headache that lasts from 4 to 72 h. The headache is often accompanied by nausea, vomiting, phonophobia and photophobia, and may be worsened by physical exercise. The trigeminovascular system (TVS) is speculated to have an important role in migraines, although the pathophysiology of this disorder remains to be elucidated. Trigeminal ganglion (TG) and spinal trigeminal nucleus caudalis (TNC) are important components of the TVS. Several clinical cases have provided evidence for the involvement of the brainstem in migraine initiation. Electrical stimulation of the trigeminal ganglion (ESTG) in rats can activate TVS during a migraine attack. Calcitonin gene-related peptide (CGRP) is an important vasoactive compound produced following TVS activation. Numerous studies have revealed that adenosine and its receptors have an important role in pain transmission and regulation process. However, only a few studies have examined whether adenosine A2a receptor (A2aR) and adenosine A1 receptor (A1R) are involved in migraine and nociceptive pathways. In the present study, CGRP, A2aR and A1R expression levels were detected in the TG and TNC of ESTG models through reverse transcription-quantitative polymerase chain reaction and western blot analysis. Tianshu capsule (TSC), a type of Chinese medicine, was also used in the ESTG rat models to examine its influence on the three proteins. Results demonstrated that CGRP, A2aR and A1R mediated pain transmission and the regulation process during migraine and the expression of the three proteins was regulated by TSC.

14.
World Neurosurg ; 88: 289-296, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26746335

RESUMO

BACKGROUND: There have yet to be any large-scale studies in China on headaches after traumatic brain injury (TBI). We evaluate the incidence of headache after TBI and investigate risk factors and functional outcome in a large tertiary center with a high caseload. METHODS: A total of 543 patients (82% men, 18% women) with a mean age of 48.4 ± 18.6 years presenting with TBI were prospectively enrolled in this study between March 2011 and July 2013. Patient demographics, severity of TBI, incidence and classification of headache, and treatment information were collected during initial hospitalization and at 3, 6, and 12 months follow-up. RESULTS: Of our 543 patients (82% men, 18% women), 62% were injured in motor vehicle collisions and 27% in falls. Most patients (97%) were considered to have mild TBI. Follow-up rates at 3, 6, and 12 months were 91%, 75%, and 61%, respectively. Only 12% of patients reported pre-TBI headaches, whereas 58% of respondents reported headache at 3 months follow-up, 54% at 6 months follow-up, and 49% at 1 year follow-up. No statistically significant correlations between age, sex, or TBI severity and posttraumatic headaches were observed. CONCLUSIONS: We present the findings of the first study on headaches after TBI in China. Headaches were found to occur in most patients with TBI and persisted through the first year after injury. The incidence of posttraumatic headache observed here is comparable with previously published studies outside China.


Assuntos
Lesões Encefálicas/diagnóstico , Lesões Encefálicas/epidemiologia , Cefaleia/diagnóstico , Cefaleia/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Idoso , Causalidade , China/epidemiologia , Comorbidade , Feminino , Humanos , Incidência , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Distribuição por Sexo , Índices de Gravidade do Trauma , Adulto Jovem
15.
Gene ; 577(1): 89-95, 2016 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-26611525

RESUMO

The purpose of this study was to establish a rat model of a brain injury with tracheotomy and compared the wetting effects of different airway humidification liquids, afterward, the best airway humidification liquid was selected for the clinical trial, thus providing a theoretical basis for selecting a proper airway humidification liquid in a clinical setting. Rats were divided into a sham group, group A (0.9% NaCl), group B (0.45% NaCl), group C (0.9% NaCl+ambroxol) and group D (0.9% NaCl+Pulmicort). An established rat model of traumatic brain injury with tracheotomy was used. Brain tissue samples were taken to determine water content, while lung tissue samples were taken to determine wet/dry weight ratio (W/D), histological changes and expression levels of SP-A mRNA and SP-A protein. 30 patients with brain injury and tracheotomy were selected and divided into two groups based on the airway humidification liquid instilled in the trachea tube, 0.45% NaCl and 0.9% NaCl+ambroxol. Blood was then extracted from the patients to measure the levels of SP-A, interleukin-6 (IL-6), interleukin-8 (IL-8) and tumour necrosis factor-α (TNF-α). The difference between group C and other groups in lung W/D and expression levels of SP-A mRNA and SP-A protein was significant (P<0.05). In comparison, the histological changes showed that the lung tissue damage was smallest in group C compared to the three other groups. Aspect of patients, 0.45% NaCl group and 0.9% NaCl+ambroxol group were significantly different in the levels of SP-A, IL-6, IL-8 and TNF-α (P<0.01). In the present study, 0.9% NaCl+ambroxol promote the synthesis and secretion of pulmonary surfactant, and has anti-inflammatory and antioxidant effects, which inhibit the release of inflammatory factors and cytokines, making it an ideal airway humidification liquid.


Assuntos
Ambroxol/farmacologia , Lesões Encefálicas/tratamento farmacológico , Budesonida/farmacologia , Proteína A Associada a Surfactante Pulmonar/metabolismo , Surfactantes Pulmonares/metabolismo , Adulto , Animais , Encéfalo/patologia , Química Encefálica , Lesões Encefálicas/patologia , Modelos Animais de Doenças , Humanos , Umidade , Pulmão/química , Pulmão/patologia , Masculino , Pessoa de Meia-Idade , Ratos , Ratos Sprague-Dawley , Cloreto de Sódio , Traqueotomia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA