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1.
BMC Public Health ; 24(1): 1169, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38664808

RESUMO

BACKGROUND: The emergence of the COVID-19 pandemic has sparked unprecedented global challenges. This study intends to investigate changes in the physical fitness of students aged 6-22 during the COVID-19 pandemic and to assess how the pandemic lockdown period affected these markers. METHODS: According to the National Student Physical Health Standard, a stratified cluster sampling method was used to evaluate the body shape, body function, and physical fitness of children and adolescents (n = 8092) in Xi'an from 2019 to 2021. This study uses SPSS 26.0 (IBM, Chicago, IL, USA) for data statistics and analysis. The connection between physical fitness and years was measured using the one-variable analysis in the general linear model (GLM). Independent t-tests were used to determine the sex (male/female) and area (urban/rural) differences. RESULTS: During the lockdown period, Body Mass Index (BMI) and flexibility showed an upward trend, while aerobic, strength, speed, and endurance showed a downward trend. In addition to the BMI of middle and high school students, almost all indicators show significant sex differences. There are urban-rural differences in some indicators, such as chin-ups. CONCLUSION: During the pandemic of COVID-19, the physical fitness of children and adolescents in Xi'an did not change significantly, and there were slight differences among different grades. During the pandemic lockdown period, lifestyle changes and reduced outdoor activities for children and adolescents may be the reasons for the changing trend of various indicators.


Assuntos
COVID-19 , Aptidão Física , Quarentena , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Masculino , Feminino , Criança , Estudos Transversais , Adolescente , China/epidemiologia , Adulto Jovem , Índice de Massa Corporal , Estudantes/estatística & dados numéricos , Pandemias , SARS-CoV-2
2.
BMC Musculoskelet Disord ; 25(1): 15, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38166826

RESUMO

BACKGROUND: The majority of published literature clinically assesses surgical outcomes after lower limb replantation for traumatic amputations. However, patients' satisfaction and quality of life may not be accurately measured through rigid scoring using standardized patient reported outcome measures. PURPOSE: The aim of this study was to qualitatively assess patient satisfaction and factors associated with achieving good outcomes after successful lower limb replantation surgery. METHODS: A semi-structured interview was conducted with 12 patients who underwent lower limb replantation surgery following traumatic amputation injuries. The interview focused on the patients' experience and satisfaction throughout their injury, surgical journey, rehabilitation and reintegration into their communities. An inductive and deductive thematic analysis was applied using the recorded transcripts to evaluate the overall satisfaction of the patients after lower limb replantation surgery. RESULTS: The following observations emerged from the structured themes among all the patients interviewed: (1) Family and social support was significantly associated with improved qualities of life and satisfaction after lower limb replantation; (2) Patients were generally satisfied with their outcomes despite limitations in physical capabilities; (3) Satisfaction was associated with acceptance of their cosmetic deformity; (4) Social integration and being able to participate in a meaningful manner was associated with greater satisfaction after recovery. CONCLUSIONS: Patients who undergo lower limb replantation can have a significantly improved quality of life if they have strong social support, are able to contribute in a meaningful manner to their communities after surgery, and are accepting of their cosmetic deficiencies.


Assuntos
Amputação Traumática , Satisfação do Paciente , Humanos , Qualidade de Vida , Reimplante , Amputação Traumática/cirurgia , Extremidade Inferior/cirurgia
3.
BMC Public Health ; 23(1): 1797, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37715140

RESUMO

BACKGROUND: In this study, by analyzing the correlation between various components of health-related physical fitness (HPF) and liver function indicators, the indicators of physical fitness that were highly correlated with liver function and could be monitored at home were screened to prevent more serious liver disease in the future, and to provide experimental basis for prescribing personalized exercise. METHODS: A total of 330 faculties (female = 198) of a university were recruited. The indicators of HPF and liver function were measured. Spearman correlation analysis, multivariate linear regression, and cross-lagged panel model was used to data statistics. RESULTS: In males, body fat (BF) was positively correlated with alanine aminotransferase (ALT); vital capacity and the vital capacity index were positively correlated with albumin; and vertical jump was positively correlated with globulin and negatively correlated with the albumin-globulin ratio (P < 0.05). However, there was no significant correlation among all indicators controlled confounding factors. In females, BF was negatively correlated with direct bilirubin; VO2max was positively correlated with indirect bilirubin; and vertical jump was positively correlated with the albumin-globulin ratio and significantly negatively correlated with globulin (P < 0.05). Controlled confounding factors, body fat percentage was positively correlated with globulin (ß = 0.174) and negatively correlated with direct bilirubin (ß = -0.431), and VO2max was positively correlated with indirect bilirubin (ß = 0.238, P < 0.05). Cross-lagged panel analysis showed that BF percentage can negatively predict direct bilirubin levels with great significance (ß = -0.055, P < 0.05). CONCLUSIONS: HPF may play a crucial role in liver function screening, particularly for female faculty members. For males, BF, vertical jump, vital capacity and vital capacity index could be associated with liver function but are susceptible to complex factors such as age, smoking, diabetes, and hypertension. In females, BF percentage is an important predictor of abnormal liver function in addition to VO2max and vertical jump, which are not affected by complex factors.


Assuntos
Bilirrubina , Aptidão Física , Masculino , Humanos , Feminino , Estudos Transversais , Albuminas , Fígado
4.
Can Assoc Radiol J ; 74(1): 192-201, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36036231

RESUMO

Achieving parity in representation within the field of Interventional Radiology (IR) across women and specific subsets of minority groups has been a challenge. The lack of a strongly diverse physician workforce in gender, race, and ethnicity suggests suboptimal recruitment after, during as well prior to IR training. There is a dearth of studies which effectively characterize the national demographic trends of the evolving IR workforce. This has prevented an accurate appraisal of continuing efforts to narrow the gaps in physician workforce diversity across the field of IR. To support these needs, this article illustrates historic trends while providing contemporary data that canvasses the status of diversity within the current IR physician and IR trainee workforce. It highlights the representation of those individuals historically underrepresented in medicine as well as women. It also highlights current obstacles to achieving equity, diversity, and inclusion within the field of IR as well as existing efforts that have been employed to mitigate this gap.


Assuntos
Médicos , Radiologia Intervencionista , Humanos , Feminino , Estados Unidos , América do Norte , Etnicidade , Recursos Humanos
5.
Am J Respir Cell Mol Biol ; 65(4): 442-460, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34101541

RESUMO

Alveolar epithelial type 2 cells (AEC2s), the facultative progenitors of lung alveoli, are typically identified through the use of the canonical markers, SFTPC and ABCA3. Self-renewing AEC2-like cells have been generated from human induced pluripotent stem cells (iPSCs) through the use of knock-in SFTPC fluorochrome reporters. However, developmentally, SFTPC expression onset begins in the fetal distal lung bud tip and thus is not specific to mature AEC2s. Furthermore, SFTPC reporters appear to identify only those iPSC-derived AEC2s (iAEC2s) expressing the highest SFTPC levels. Here, we generate an ABCA3 knock-in GFP fusion reporter (ABCA3:GFP) that enables the purification of iAEC2s while allowing visualization of lamellar bodies, organelles associated with AEC2 maturation. Using an SFTPCtdTomato and ABCA3:GFP bifluorescent line for in vitro distal lung-directed differentiation, we observe later onset of ABCA3:GFP expression and broader identification of the subsequently emerging iAEC2 population based on ABCA3:GFP expression compared with SFTPCtdTomato expression. Comparing ABCA3:GFP/SFTPCtdTomato double-positive with ABCA3:GFP single-positive (SP) cells by RNA sequencing and functional studies reveals iAEC2 cellular heterogeneity with both populations functionally processing surfactant proteins but the SP cells exhibiting faster growth kinetics, increased clonogenicity, increased expression of progenitor markers, lower levels of SFTPC expression, and lower levels of AEC2 maturation markers. Over time, we observe that each population (double-positive and SP) gives rise to the other and each can serve as the parents of indefinitely self-renewing iAEC2 progeny. Our results indicate that iAEC2s are a heterogeneous population of cells with differing proliferation versus maturation properties, the majority of which can be tracked and purified using the ABCA3:GFP reporter or surrogate cell surface proteins, such as SLC34A2 and CPM.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Células Epiteliais Alveolares/citologia , Células-Tronco Pluripotentes Induzidas/citologia , Alvéolos Pulmonares/citologia , Proteína C Associada a Surfactante Pulmonar/metabolismo , Diferenciação Celular/fisiologia , Células Epiteliais/metabolismo , Humanos , Pulmão/metabolismo , Proteínas Associadas a Surfactantes Pulmonares/metabolismo
6.
Chemistry ; 27(16): 5277-5282, 2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33438792

RESUMO

The Z-scheme process is a photoinduced electron-transfer pathway in natural oxygenic photosynthesis involving electron transport from photosystem II (PSII) to photosystem I (PSI). Inspired by the interesting Z-scheme process, herein a photocatalytic hydrogen evolution reaction (HER) employing chlorophyll (Chl) derivatives, Chl-1 and Chl-2, on the surface of Ti3 C2 Tx MXene with two-dimensional accordion-like morphology, forming Chl-1@Chl-2@Ti3 C2 Tx composite, is demonstrated. Due to the frontier molecular orbital energy alignments of Chl-1 and Chl-2, sublayer Chl-1 is a simulation of PSI, whereas upper layer Chl-2 is equivalent to PSII, and the resultant electron transport can take place from Chl-2 to Chl-1. Under the illumination of visible light (>420 nm), the HER performance of Chl-1@Chl-2@Ti3 C2 Tx photocatalyst was found to be as high as 143 µmol h-1 gcat -1 , which was substantially higher than that of photocatalysts of either Chl-1@Ti3 C2 Tx (20 µmol h-1 g-1 ) or Chl-2@Ti3 C2 Tx (15 µmol h-1 g-1 ).


Assuntos
Clorofila , Titânio , Hidrogênio , Complexo de Proteína do Fotossistema I/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo
7.
BMC Geriatr ; 20(1): 257, 2020 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-32723295

RESUMO

BACKGROUND: Many older adults in the U.S. do not achieve the recommended amount of physical activity (PA) to fully realize a myriad of health benefits. Adiposity is one of those important correlates of PA and sedentary behaviors. However, the full extent to which adiposity is associated with PA and stationary time (STA) is uncertain. Therefore, we examined the association of adiposity with objectively measured PA and STA in black and white older adults. METHODS: We conducted a cross-sectional study of older adults enrolled in the REasons for Geographic and Racial Differences in Stroke (REGARDS) Study 2003-2007 who participated in an ancillary accelerometer study 2009-2013. Assessment of body mass index (BMI) and waist circumference (WC) was completed during an in-home visit in the parent study. PA was measured by Actical™ accelerometers, which provided estimates of moderate-to-vigorous-intensity PA (MVPA), light-intensity PA (LPA), and STA for 4-7 consecutive days. Data from accelerometers were standardized to square root percentages of total wear time per day (SqrtMVPA%, SqrtLPA%, and SqrtSTA%). Interactions were tested for BMI and WC by race and sex, separately. RESULTS: Data were available for 7873 participants (69.8 ± 8.7 yr, 54.2% women, 31.5% African American). In mixed linear regression models, significant interactions existed in BMI by race and sex for the SqrtMVPA%, WC by race and sex for the SqrtMVPA% and the SqrtLPA% model(p < 0.05). No interaction was significant for the logistic model of meeting the PA guideline or not. In subgroup analyses, BMI was inversely associated with SqrtMVPA%, SqrtLPA%, and positively related to SqrtSTA% in black women, white men and white women after adjustments. Similar patterns were observed between WC and SqrtMVPA%, SqrtLPA%, and SqrtSTA% in all groups, respectively. However, BMI was not associated with SqrtMVPA% in black men. Those with higher BMI or WC were less likely to meet the PA guideline in all groups. CONCLUSIONS: Adiposity was inversely associated with higher levels of MVPA/LPA and positively associated with higher levels of STA among black and white older adults. Prevention efforts aimed at promoting weight control may be beneficial to prevent physical inactivity and sedentary lifestyle among older adults.


Assuntos
Adiposidade , Comportamento Sedentário , Acelerometria , Idoso , Índice de Massa Corporal , Estudos Transversais , Exercício Físico , Feminino , Humanos , Masculino
8.
Med Microbiol Immunol ; 208(6): 781-792, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31187242

RESUMO

Staphylococcal enterotoxins (SEs), as typical superantigens, exhibit promising antitumour activity in the clinic, but their unavoidable side effects related to fever and emesis seriously limit their application for the treatment of malignant tumours. Fortunately, the identification of Staphylococcal enterotoxin-like toxins (SEls), which possess amino acid sequences similar to those of classical SEs but exhibit no or low emetic activity, has provided a set of potential immunomodulatory candidates for cancer therapy. The aim of this study was to examine the effect of SElQ on lymphocyte activation and to further demonstrate its antitumour activity both in vitro and in vivo. High-purity SElQ was successfully harvested, and in vitro results confirmed that SElQ can significantly activate mouse- and human-derived lymphocytes in a dose-dependent manner, particularly CD4+ and CD8+ T cells, which showed significant increases in both percentage and absolute number. Further examination revealed that in addition to the originally recognized TCR Vß5 and 21, TCR Vß14, 17 and 18 were activated in SElQ-induced human PBMCs. Moreover, the expression of IL-2 and IFN-γ was significantly upregulated in vitro and in vivo after SElQ treatment. Based on the findings that SElQ induces lymphocyte activation and cytokine release, we then confirmed its antitumour activity both in vitro and in vivo. The data showed that treatment with a low concentration of SElQ (30 µg/mouse) could inhibit the growth of tumours by approximately 30% and no significant toxicity was observed. Taken together, our results demonstrated that SElQ can significantly induce T cell activation and cytokine release and further elicit substantial antitumour activity and thus provide support for the potential application of SElQ in cancer immunotherapy.


Assuntos
Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Enterotoxinas/metabolismo , Ativação Linfocitária/efeitos dos fármacos , Superantígenos/metabolismo , Animais , Células Cultivadas , Citocinas/metabolismo , Relação Dose-Resposta Imunológica , Feminino , Voluntários Saudáveis , Humanos , Camundongos Endogâmicos BALB C , Receptores de Antígenos de Linfócitos T/metabolismo
9.
J Cell Mol Med ; 22(3): 1627-1639, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29278305

RESUMO

Successful isolation of human endometrial stem cells from menstrual blood, namely menstrual blood-derived endometrial stem cells (MenSCs), has provided enticing alternative seed cells for stem cell-based therapy. MenSCs are enriched in the self-regenerative tissue, endometrium, which shed along the periodic menstrual blood and thus their acquisition involves no physical invasiveness. However, the impact of the storage duration of menstrual blood prior to stem cell isolation, the age of the donor, the number of passages on the self-renewing of MenSCs, the paracrine production of biological factors in MenSCs and expression of adhesion molecules on MenSCs remain elusive. In this study, we confirmed that MenSCs reside in shedding endometrium, and documented that up to 3 days of storage at 4°C has little impact on MenSCs, while the age of the donor and the number of passages are negatively associated with proliferation capacity of MenSCs. Moreover, we found that MenSCs were actually immune-privileged and projected no risk of tumour formation. Also, we documented a lung- and liver-dominated, spleen- and kidney-involved organic distribution profile of MenSC 3 days after intravenous transfer into mice. At last, we suggested that MenSCs may have potentially therapeutic effects on diseases through paracrine effect and immunomodulation.


Assuntos
Proliferação de Células , Endométrio/citologia , Menstruação/sangue , Células-Tronco/citologia , Adulto , Animais , Diferenciação Celular , Células Cultivadas , Feminino , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Transplante de Células-Tronco/métodos , Transplante Heterólogo , Adulto Jovem
10.
J Exp Bot ; 68(9): 2231-2244, 2017 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-28398585

RESUMO

Immunofluorescence microscopy (IFM) and immunogold transmission electron microscopy (TEM) are the two main techniques commonly used to detect polysaccharides in plant cell walls. Both are important in localizing cell wall polysaccharides, but both have major limitations, such as low resolution in IFM and restricted sample size for immunogold TEM. In this study, we have developed a robust technique that combines immunocytochemistry with scanning electron microscopy (SEM) to study cell wall polysaccharide architecture in xylem cells at high resolution over large areas of sample. Using multiple cell wall monoclonal antibodies (mAbs), this immunogold SEM technique reliably localized groups of hemicellulosic and pectic polysaccharides in the cell walls of five different xylem structures (vessel elements, fibers, axial and ray parenchyma cells, and tyloses). This demonstrates its important advantages over the other two methods for studying cell wall polysaccharide composition and distribution in these structures. In addition, it can show the three-dimensional distribution of a polysaccharide group in the vessel lateral wall and the polysaccharide components in the cell wall of developing tyloses. This technique, therefore, should be valuable for understanding the cell wall polysaccharide composition, architecture and functions of diverse cell types.


Assuntos
Parede Celular/ultraestrutura , Imuno-Histoquímica/métodos , Microscopia Eletrônica de Varredura/métodos , Polissacarídeos/ultraestrutura , Vitis/ultraestrutura , Xilema/ultraestrutura , Pectinas/ultraestrutura
11.
Int J Mol Sci ; 18(6)2017 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-28590426

RESUMO

Down's syndrome (DS), the most common genetic cause of significant intellectual disability in children and adults is caused by the trisomy of either all or a part of human chromosome 21 (HSA21). Patients with DS mostly suffer from characteristic tumor types. Although individual patients of DS are at a higher risk for acute leukemia and testicular cancers, other types of solid tumors including breast cancers are mostly uncommon and have significantly lower-than-expected age-adjusted incidence rates. Except for an increased risk of retinoblastomas, and lymphomas, the risk of developing solid tumors has been found to be lower in both children and adults, and breast cancer was found to be almost absent (Hasle H., The Lancet Oncology, 2001). A study conducted in the United States found only one death when 11.65 were expected (Scholl T et al., Dev Med Child Neurol. 1982). A recent study examined mammogram reports of women with DS treated in the largest medical facility specifically serving adults with DS in the United States. It was found that only 0.7% women with DS had been diagnosed with breast cancers (Chicoine B et al., Intellect Dev Disabil. 2015). Here we describe a case of breast cancer in a 25-year-old patient with DS. The disease was presented as lymph node positive carcinoma with alterations of tumor suppressor genes characteristic to the triple negative breast cancer subtype. Comprehensive Genomic Profiling (CGP) revealed a wild-type status for BRCA1. The CGP report showed a frameshift mutation, A359fs*10 of the tumor suppressor gene INPP4B and another frameshift mutation, R282fs*63 of tumor suppressor gene TP53 in the tumor biopsy as characteristically found in triple-negative breast cancers. The VUS (Variance of Unknown Significance) alteration(s) were identified in ASXL1 (L1395V), NTRK1 (G18E), DDR2 (I159T), RUNX1 (amplification), ERG (amplification), SOX2 (T26A), FAM123B (G1031D), and HNF1A (A301T). Bonafide cancer-related genes of chromosome 21 amplified in the patient's tumor are RUNX1 and ERG genes. After the completion of the radiation, the patient was placed on everolimus which was based on the result of her CGP report. Thus, post-mastectomy radiation therapy was completed with a recommendation for everolimus for one year. During the time of writing of this report, no metastatic lesions were identified. The patient currently has no evidence of disease.


Assuntos
Síndrome de Down/complicações , Neoplasias de Mama Triplo Negativas/diagnóstico , Neoplasias de Mama Triplo Negativas/etiologia , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores Tumorais , Cromossomos Humanos Par 21 , Hibridização Genômica Comparativa , Feminino , Humanos , Imuno-Histoquímica , Mutação , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Trissomia
12.
J Environ Manage ; 189: 29-35, 2017 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-28002779

RESUMO

Chlorinated paraben, namely, methyl 3, 5-dichloro-4-hydroxybenzoate (MDHB) is the by-product of chlorination disinfection of paraben and frequently detected in the aquatic environments, which exhibited higher persistence and toxicity than paraben itself. In this paper, the combined irradiation and biological treatment process was employed to investigate the removal of MDHB from aqueous solution. The results showed that the removal efficiency of MDHB and total organic carbon (TOC) by irradiation process increased with radiation dose no matter what the initial concentration of MDHB was. The maximum removal efficiency of MDHB was 100%, 91.1%, 93%, respectively, for the initial concentration of MDHB of 1 mg/L, 5 mg/L and 10 mg/L with the radiation dose of 800 Gy. However, the maximum removal efficiency of TOC among all the experimental groups was only 15.3% obtained with the initial concentration of 1 mg/L at dose of 800 Gy. The subsequent biological treatment enhanced the mineralization of MDHB. The suitable radiation dose for the subsequent biological treatment was determined to be 600 Gy. In this case the removal efficiency of TOC increased to about 70%. Compared to the single biological treatment, the integrated irradiation and biological treatment significantly increase the degradation and mineralization of MDHB. Moreover, the dechlorination efficiency reached 77.4% during the integrated irradiation and biological treatment process. In addition, eight intermediates were identified during the combined process and the possible degradation pathway was proposed.


Assuntos
Clorobenzoatos/química , Parabenos/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Biodegradação Ambiental , Carbono/química , Carbono/isolamento & purificação , Clorobenzoatos/metabolismo , Raios gama , Halogenação , Parabenos/metabolismo , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/metabolismo
13.
Landsc Urban Plan ; 167: 240-248, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-29170571

RESUMO

Background: To test inter-rater reliability of the online Microscale Audit of Pedestrian Streetscapes (MAPS) tool between raters with varying familiarities of Phoenix, Arizona. Methods: The online MAPS tool, based on the MAPS in-field audit tool and scoring system, was used for audits. Sixty route pairs, 141 segment pairs, and 92 crossing pairs in Phoenix were included. Each route, segment or crossing was audited by two independent raters: one rater in Phoenix and the other in San Diego, California, respectively. Item, subscale scores, and total scores reliability analyses were computed using Kappa or intra-class correlation coefficient (ICC). Results: The route overall score had substantial reliability (ICC: 0.832). Of the route subscale and overall scores, sixteen out of twenty had moderate to substantial reliability (ICC: 0.616-0.906), and the four subscales had fair reliability (ICC: 0.409-0.563). Sixteen out of twenty scores in segment and crossing sections demonstrated fair to substantial reliability (ICC: 0.448-0.897), and the remaining four had slight reliability (ICC: 0.348-0.364). Conclusions: Most of the online MAPS items, subscales, and overall scores demonstrated fair to substantial reliability between raters with varied familiarities of the Phoenix area. Results support use of online MAPS to measure microscale elements of the built environment by raters unfamiliar with a region.

14.
J Strength Cond Res ; 30(7): 1906-16, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27331914

RESUMO

Yu, J, Sun, Y, Yang, C, Wang, D, Yin, K, Herzog, W, and Liu, Y. Biomechanical insights into differences between the mid-acceleration and maximum velocity phases of sprinting. J Strength Cond Res 30(7): 1906-1916, 2016-Investigating the differences between distinct phases of sprint running may increase the knowledge about the specific physical abilities needed for different phases of sprinting. Differences between the mid-acceleration and maximum velocity phases of sprint running have not yet been adequately investigated. Twenty male sprinters performed maximum-effort sprint runs, and measurements were made at 12 m from start for the mid-acceleration phase and at 40 m from the start for the maximum velocity phase. Kinematic data and ground reaction forces (GRFs) were collected at a rate of 200 and 1000 Hz, respectively. Intersegmental dynamics analysis was performed to investigate the interaction of muscle torque (MUS) with other passive torques. The peak horizontal braking force was significantly lower for the acceleration compared with that for the maximal velocity phase, whereas the peak horizontal propulsive force was similar for both phases. The peak MUS at the hip and knee joints for the braking phase was significantly smaller in the acceleration phase than in the maximum velocity phase. In conclusion, compared with the maximum velocity phase, the lower horizontal braking force was the primary cause for the increase in running velocity during the mid-acceleration phase. The force produced by lower limb muscles required to counteract external torques caused by the horizontal braking force in the braking phase was smaller during the acceleration phase than the maximum velocity phase. Therefore, training aimed at reducing the horizontal braking force might be more important than increasing the force produced by the lower limb muscles for success of the mid-acceleration phase.


Assuntos
Aceleração , Extremidade Inferior/fisiologia , Músculo Esquelético/fisiologia , Corrida/fisiologia , Fenômenos Biomecânicos , Articulação do Quadril/fisiologia , Humanos , Articulação do Joelho/fisiologia , Masculino , Torque , Adulto Jovem
15.
Plant Physiol ; 161(3): 1529-41, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23292789

RESUMO

Vascular occlusions are common structural modifications made by many plant species in response to pathogen infection. However, the functional role(s) of occlusions in host plant disease resistance/susceptibility remains controversial. This study focuses on vascular occlusions that form in stem secondary xylem of grapevines (Vitis vinifera) infected with Pierce's disease (PD) and the impact of occlusions on the hosts' water transport and the systemic spread of the causal bacterium Xylella fastidiosa in infected vines. Tyloses are the predominant type of occlusion that forms in grapevine genotypes with differing PD resistances. Tyloses form throughout PD-susceptible grapevines with over 60% of the vessels in transverse sections of all examined internodes becoming fully blocked. By contrast, tylose development was mainly limited to a few internodes close to the point of inoculation in PD-resistant grapevines, impacting only 20% or less of the vessels. The extensive vessel blockage in PD-susceptible grapevines was correlated to a greater than 90% decrease in stem hydraulic conductivity, compared with an approximately 30% reduction in the stems of PD-resistant vines. Despite the systemic spread of X. fastidiosa in PD-susceptible grapevines, the pathogen colonized only 15% or less of the vessels in any internode and occurred in relatively small numbers, amounts much too small to directly block the vessels. Therefore, we concluded that the extensive formation of vascular occlusions in PD-susceptible grapevines does not prevent the pathogen's systemic spread in them, but may significantly suppress the vines' water conduction, contributing to PD symptom development and the vines' eventual death.


Assuntos
Doenças das Plantas/microbiologia , Feixe Vascular de Plantas/microbiologia , Vitis/microbiologia , Resistência à Doença/imunologia , Corpos de Inclusão/metabolismo , Corpos de Inclusão/ultraestrutura , Doenças das Plantas/imunologia , Caules de Planta/imunologia , Caules de Planta/microbiologia , Feixe Vascular de Plantas/ultraestrutura , Vitis/imunologia , Vitis/ultraestrutura , Água , Xylella/fisiologia , Xilema/microbiologia , Xilema/ultraestrutura
16.
BMC Womens Health ; 14: 62, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24885417

RESUMO

BACKGROUND: High levels of physical activity (PA) and cardiorespiratory fitness (CRF) are each associated with a favorable cardiovascular disease (CVD) risk profile. However, the relationship between CRF and obesity is still inconsistent across studies, and there has been no thorough exploration of the independent contribution of CRF to different CVD risk factors in Chinese women. This study investigated the relationship between CRF and CVD risk factors in 40-49 year old women in Beijing. METHODS: The study included 231 urban-dwelling asymptomatic 40-49 year old women. Body mass index (BMI), body fat percentage (BF%), blood glucose, blood lipids, blood pressure, and pulse wave velocity (PWV) were measured at rest. Cycle ergometer exercise tests were conducted to assess CRF as indicated by maximal oxygen uptake (VO(2max)). Participants were categorized into three CRF levels (low, moderate and high). RESULTS: High CRF level was associated with significantly less BF%, lower PWV, and higher weekly physical activity compared with low and moderate CRF (P < 0.05). Compared to high CRF, the odds ratios for having ≥3 main CVD risk factors (overweight, hypertension, and dyslipidemia) in low and moderate CRF were 2.09 (95% CI: 1.48-2.94) and 1.84 (95% CI: 1.29-2.62), respectively. The proportion of participants with clinical ST segment depression and prolonged QTC interval during cycle ergometer testing was significantly higher in women with low CRF. CONCLUSIONS: Overall, Chinese middle-aged women demonstrated a moderate level of CRF. CRF was independently associated with CVD risk factors, including overweight, hypertension, dyslipidemia, arterial stiffness, and abnormal ECG during exercise, with the least fit women exhibiting the highest number of CVD risk factors.


Assuntos
Doenças Cardiovasculares/fisiopatologia , Atividade Motora/fisiologia , Aptidão Física/fisiologia , Adulto , Consumo de Bebidas Alcoólicas , Glicemia/fisiologia , Pressão Sanguínea/fisiologia , Distribuição da Gordura Corporal , Índice de Massa Corporal , Doenças Cardiovasculares/sangue , China , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Estudos Transversais , Teste de Esforço , Feminino , Humanos , Modelos Logísticos , Pessoa de Meia-Idade , Sobrepeso , Análise de Onda de Pulso , Fatores de Risco , Fumar , Triglicerídeos/sangue
17.
Sci Rep ; 14(1): 6341, 2024 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-38491143

RESUMO

The conservative treatment for Kohler's disease will take several months, but some patients still have flatfoot and persistent pain. From October 2013 to July 2015, 3 children with Kohler's disease underwent navicular decompression and micro-circulation reconstruction surgery in our hospital. All the patients have received conservative treatment for more than 3 months and the effect was poor. X-ray showed the bone density of navicular increased significantly. All patients were followed up over 1 year. The 3 patients recovered well. VAS score decreased from 7.0 to 2.6 at 1 month after the operation. The pain symptom disappeared completely on 3 months after surgery. The density of navicular bone recovered to normal. Navicular decompression and micro-circulation reconstruction surgery may quickly improve the ischemic status of navicular bone, alleviate pain symptom and enable patients to resume normal activity as soon as possible.


Assuntos
Pé Chato , Osteocondrite , Osteocondrose , Ossos do Tarso , Criança , Humanos , Dor/etiologia , Dor/cirurgia
18.
Sci Rep ; 14(1): 14581, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38918404

RESUMO

Efficient semantic segmentation of large-scale point cloud scenes is a fundamental and essential task for perception or understanding the surrounding 3d environments. However, due to the vast amount of point cloud data, it is always a challenging to train deep neural networks efficiently and also difficult to establish a unified model to represent different shapes effectively due to their variety and occlusions of scene objects. Taking scene super-patch as data representation and guided by its contextual information, we propose a novel multiscale super-patch transformer network (MSSPTNet) for point cloud segmentation, which consists of a multiscale super-patch local aggregation (MSSPLA) module and a super-patch transformer (SPT) module. Given large-scale point cloud data as input, a dynamic region-growing algorithm is first adopted to extract scene super-patches from the sampling points with consistent geometric features. Then, the MSSPLA module aggregates local features and their contextual information of adjacent super-patches at different scales. Owing to the self-attention mechanism, the SPT module exploits the similarity among scene super-patches in high-level feature space. By combining these two modules, our MSSPTNet can effectively learn both local and global features from the input point clouds. Finally, the interpolating upsampling and multi-layer perceptrons are exploited to generate semantic labels for the original point cloud data. Experimental results on the public S3DIS dataset demonstrate its efficiency of the proposed network for segmenting large-scale point cloud scenes, especially for those indoor scenes with a large number of repetitive structures, i.e., the network training of our MSSPTNet is much faster than other segmentation networks by a factor of tens to hundreds.

19.
J Biomech ; 166: 112029, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38447428

RESUMO

This study investigates the impact of increasing backpack load on the gait of adolescents during stair descent. Sixteen healthy male students (age = 12.9 ± 0.6 years) were required to descend the stairs in 4 loaded conditions. The kinematic, kinetic, and EMG data were collected synchronously and gait parameters, especially indicators of balance control, were analyzed. The posterior tilt angles (COM-COP IA in the sagittal plane) (0 %-42 %, 48 %-53 %, 58 %-91 %, p < 0.01), trunk anterior tilt angles (9-33 %, 51-65 %, p < 0.01), and CV of stride length (p < 0.01) increased with the backpack load. The COM-Step edge separation decreased with the increased backload (p < 0.01). In addition, the hip flexion torque (25-40 %, 45-51 %, p < 0.01), the rectus femoris activation, and the hip stiffness increased significantly as the load up to 15 % Body Weight (BW)and 20 % BW. The increasing backpack load may affect adolescent's stair descent gait. Especially as the load was up to 15 % BW, the adolescents' bodies tended to tilt backwards relative to the support foot during the single stance phase. They may activate the hip flexors and tilt forward the trunk to recover from the balance perturbation, which was associated with increased hip flexion torques. This adjustment was more pronounced with the increasing backpack load. However, excessive forward flexion may increase the risk of forward falls. The boundaries of adjustment need further research in the future. Findings from this study provide baseline information on the intrinsic mechanisms of balance control during stair descent.


Assuntos
Marcha , Caminhada , Humanos , Masculino , Adolescente , Criança , Caminhada/fisiologia , Marcha/fisiologia , Extremidade Inferior/fisiologia , , Músculo Quadríceps , Peso Corporal , Fenômenos Biomecânicos
20.
Mater Today Bio ; 26: 101105, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38933416

RESUMO

In tumor treatment, the deposition of nanoenzymes in normal tissues and cause potential side effects are unavoidable. Here, we designed an intelligent biomimetic nanoenzymes carrier platform (MSCintelligent) that endows the carrier platform with "wisdom" by introducing Affibody-Notch(core)-VP64-GAL4/UAS-HSV-TK artificial signal pathways to mesenchymal stem cells (MSCs). This intelligent nanoenzymes carrier platform is distinguished from the traditional targeting tumor microenvironment or enhancing affinity with tumor, which endue MSCintelligent with tumor signal recognition capacity, so that MSCintelligent can autonomously distinguish tumor from normal tissue cells and feedback edited instructions. In this study, MSCintelligent can convert tumor signals into HSV-TK instructions through artificial signal pathway after recognizing Her2 (+) tumor. Subsequently, the synthesized HSV-TK can rupture MSCintelligent under the mediation of ganciclovir, and release the preloaded Cu/Fe nanocrystal clusters to kill the tumor accurately. Meanwhile, MSCintelligent without recognizing tumors will not initiate the HSV-TK instructions, thus being unresponsive to GCV and blocking the release of nanoenzymes in normal tissues. Consequently, MSCintelligent is the first intelligent biomimetic nanoenzymes carrier platform, which represents a new biomimetic nanoenzymes targeting mode.

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