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1.
PNAS Nexus ; 3(2): pgae028, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38725530

RESUMO

Urban sustainability is a key to achieving the UN sustainable development goals (SDGs). Secure and efficient provision of food, energy, and water (FEW) resources is a critical strategy for urban sustainability. While there has been extensive discussion on the positive effects of the FEW nexus on resource efficiency and climate impacts, measuring the extent to which such synergy can benefit urban sustainability remains challenging. Here, we have developed a systematic and integrated optimization framework to explore the potential of the FEW nexus in reducing urban resource demand and greenhouse gas (GHG) emissions. Demonstrated using the Metropolis Beijing, we have identified that the optimized FEW nexus can reduce resource consumption and GHG emissions by 21.0 and 29.1%, respectively. These reductions come with increased costs compared to the siloed FEW management, but it still achieved a 16.8% reduction in economic cost compared to the business-as-usual scenario. These findings underscore the significant potential of FEW nexus management in enhancing urban resource efficiency and addressing climate impacts, while also identifying strategies to address trade-offs and increase synergies.

2.
Mol Med Rep ; 28(5)2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37732532

RESUMO

Telomere attrition plays a critical role in the reproductive aging process in humans. Telomere length (TL) is typically regulated by telomerase, the main component of which is telomerase reverse transcriptase (TERT). The aim of the present study was to investigate the changes of relative TL (RTL) and TERT expression in granulosa cells (GCs) during aging and its association with reproduction. Clinical data on the frozen­thawed embryo transfer cycles of older (>35 year old) and younger (≤35 year old) women from a single center over a 3­year period were retrospectively analyzed. Preimplantation genetic testing for chromosome aneuploidies in older women during the same period was also analyzed. Following the analysis of the data, several biological characteristics of senescent GCs were explored. In addition, a total of 160 women who were undergoing their first fresh cycle of in vitro fertilization (IVF) or intracytoplasmic sperm injection were included in the study. GCs were collected from all participants. The changes of RTL and TERT expression in GCs during aging were investigated using quantitative PCR and western blotting. The associations of RTL and TERT with IVF outcomes were also assessed. The clinical data demonstrated that the pregnancy and live birth rates of women aged >35 years were ~20% lower than those of women aged ≤35 years, and the number of embryos with aneuploidy was 7­fold of that without euploidy in the older age group. An aging­induced change in follicle stimulating hormone receptor expression was observed. A shorter TL and increased TERT expression were detected in the older women. A significant inverse correlation between the expression levels of TERT and oocyte yield was identified. However, no association of RTL and TERT with blastocyst formation rate and the probability of clinical pregnancy was detected. It may be concluded that RTL and TERT alterations in GCs are potential determinants of ovarian aging. TERT expression in GCs appears to be a potential biomarker for the prediction of ovarian response, which provides a novel strategy for the assessment of female fertility.


Assuntos
Telomerase , Adulto , Idoso , Feminino , Humanos , Masculino , Gravidez , Envelhecimento/genética , Aneuploidia , Fertilização in vitro , Células da Granulosa , Estudos Retrospectivos , Sêmen , Telomerase/genética
3.
Clin Drug Investig ; 43(4): 241-250, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36929485

RESUMO

BACKGROUND AND OBJECTIVE: Approximately 38 million people worldwide experience heart failure (HF), with more than 10 million in China. Heart failure exacerbations are the main cause of HF hospitalization, and hospitalizations are the main driver of HF-associated costs. Vericiguat is recommended to treat patients who have had worsening HF despite guideline-directed medical therapy. However, the cost effectiveness of adding vericiguat to the standard treatment of this population in China remains unclear. The objective of this study was to investigate the cost effectiveness of adding vericiguat to standard treatment in patients with HF in the Chinese population METHODS: A lifetime Markov model with a 1-month cycle length was developed to compare the cost effectiveness of vericiguat plus standard treatment versus standard treatment alone in Chinese patients with HF with reduced ejection fraction following an HF exacerbation, from the perspective of Chinese healthcare providers. The clinical data were obtained from the VICTORIA study. The cost was accessed from our institution or studies conducted in China. The primary outcome was the incremental cost-effectiveness ratio, representing incremental cost per incremental quality-adjusted life-year (QALY). Vericiguat was considered highly cost effective if the incremental cost-effectiveness ratio obtained was lower than 12,551 USD/QALY, cost effective if the incremental cost-effectiveness ratio was between 12,551 and 37,654.5 USD/QALY, and not cost effective if the incremental cost-effectiveness ratio was higher than 37,654.5 USD/QALY. A scenario analysis, one-way sensitivity analysis, and probabilistic sensitivity analysis were performed to test the robustness of the results. RESULTS: For a 67-year-old patient with HF following an HF exacerbation, the lifetime cost was 17,721 USD if vericiguat plus standard treatment was given, compared to 7907 USD if standard treatment alone was prescribed. The corresponding effectiveness was 2.20 QALY and 2.10 QALY, respectively. The incremental cost-effectiveness ratio of vericiguat plus standard treatment versus standard treatment alone in Chinese patients with HF was 89,429 USD/QALY, higher than the willingness-to-pay threshold of 37654.5 USD/QALY. The scenario analysis and sensitivity analysis showed the robustness of our results. CONCLUSIONS: The addition of vericiguat to the treatment regimen of Chinese patients with HF with reduced ejection fraction following an HF exacerbation resulted in an incremental cost-effectiveness ratio of $89,429 USD/QALY compared to standard treatment. This incremental cost-effectiveness ratio exceeds the willingness-to-pay threshold and thus, vericiguat was deemed not cost effective in the Chinese population.


Assuntos
Análise de Custo-Efetividade , Insuficiência Cardíaca , Humanos , Idoso , Volume Sistólico , População do Leste Asiático , Análise Custo-Benefício , Insuficiência Cardíaca/tratamento farmacológico , Anos de Vida Ajustados por Qualidade de Vida
4.
Aesthetic Plast Surg ; 47(2): 872-879, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36414722

RESUMO

BACKGROUND: Patients with chest keloids undergoing surgery and adjuvant radiotherapy still have a high recurrence rate, which is a critical problem. The level of keloid activity has not been studied, and a nomogram model for predicting keloid recurrence has not been established in previous studies. METHODS: A total of 145 patients with chest keloids who underwent surgery and radiotherapy between January 2015 and January 2019 at Peking Union Medical College Hospital were included in our study. Demographic and clinical features and the score of KAAS were analyzed. We compared the area under the curve (AUC) and decision curve analysis (DCA) between KAAS and the Vancouver scar scale (VSS) and established a nomogram model for predicting the risk of recurrence. We used bootstrap and calibration plots to evaluate the performance of the nomogram. RESULTS: The KAAS can predict recurrence in patients with chest keloids after surgery and radiotherapy. Areas under the curve (AUCs) of KAAS and VSS were 0.858 and 0.711, respectively (p < 0.001). Decision curve analysis (DCA) demonstrated that the KAAS was better than the VSS. Complications after treatment may be risk factors for keloid recurrence. We created a nomogram by using complications and KAAS. The AUC was 0.871 (95% CI 0.812-0.930). The ROC of the model's bootstrap was 0.865 and was well calibrated. CONCLUSIONS: The KAAS can be used to predict the recurrence and we developed a nomogram for predicting the recurrence of chest keloids after surgery and adjuvant radiotherapy. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .


Assuntos
Queloide , Humanos , Queloide/diagnóstico , Queloide/radioterapia , Queloide/cirurgia , Nomogramas , Tórax , Radioterapia Adjuvante , Recidiva , Resultado do Tratamento
5.
Environ Sci Technol ; 56(10): 6584-6595, 2022 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-35507754

RESUMO

The role of ocean carbon sinks in global climate change mitigation and carbon neutrality is still affected by lack of research. Aiming at overcoming the present limitations, a comprehensive and holistic framework and accounting method of ocean carbon sink evaluation are proposed in this study, which consider both carbon sink types and their characteristic carbon storage cycle timescales. The results show that (1) China's total ocean carbon sink is 69.83-106.46 Tg C/year, among which the mariculture, coastal wetlands, and offshore carbon sinks are 2.27-4.06, 2.86-5.85, and 64.70-96.55 Tg C/year, respectively; (2) ocean-based solutions such as coastal protection and restoration, mariculture development, ocean alkalization, ocean fertilization, and marine bioenergy with carbon capture and storage have substantial mitigation potential, but further investigation is required before large-scale deployment; (3) although China's ocean carbon sinks only counterbalanced 3.27-4.99% of its fossil fuel emissions, their tremendous enhancing potential and specific advantages cannot be ignored, and enhancing measures must be taken according to regional characteristics; (4) some uncertainties and limitations still exist, and problems such as double counting, carbon sink offset, and so forth need to be further considered. In a word, this study provides a basis for the development of ocean-based solutions on closing climate mitigation gaps.


Assuntos
Ciclo do Carbono , Sequestro de Carbono , Carbono/análise , China , Ecossistema , Oceanos e Mares
6.
Front Endocrinol (Lausanne) ; 13: 852620, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35311229

RESUMO

Background: Blastocyst biopsy has become the most mainstream biopsy method. Currently, there are two blastocyst biopsy strategies. Many studies have compared the advantages and disadvantages between blastomere and blastocyst biopsy, but fewer articles have compared the two blastocyst biopsy strategies. For the moment, no published studies have explored the entire set of information on embryo development, next-generation sequencing results, and clinical outcomes, including the baby's health status with the two blastocyst biopsy strategies. Methods: A total of 323 preimplantation genetic testing cycles from April 2018 to May 2020, including 178 cycles with Strategy A and 145 cycles with Strategy B. Strategy A was to create a laser-assisted zona pellucid opening for cleavage embryo on the third day after insemination, but Strategy B was not. Strategy A performed a biopsy for artificially assisted hatching blastocysts, while Strategy B performed a biopsy for expanded blastocysts on day 5 or 6. In this study, embryo development, next-generation sequencing results, pregnancy outcomes, and offspring health of the two strategies were compared and analyzed. Results: There were no statistical differences between the two groups in the rate of fertilization, blastocyst and abortion. The rate of cleavage from Strategy A was slightly higher than Strategy B, and the rate of high-quality cleavage embryo was lower than Strategy B, while the rate of high-quality blastocyst was higher than Strategy B. The rate of no-results blastocyst was significantly lower than Strategy B. In particular, the rate of biochemical pregnancy, clinical pregnancy, and live birth of Strategy A were significantly lower than those of Strategy B. The average Apgar scores of newborns were ≥8 in both groups, and there was no significant difference in average height and weight. In Strategy A, a baby was born with thumb syndactyly, and Strategy B had no congenital disabilities. Conclusions: Blastocyst biopsy strategy without laser-assisted zona pellucid drilling on day 3 achieves better clinical treatment effects. Therefore, Strategy B is an optimal treatment regime for PGT.


Assuntos
Diagnóstico Pré-Implantação , Aneuploidia , Biópsia , Blastocisto , Feminino , Testes Genéticos/métodos , Humanos , Recém-Nascido , Gravidez , Diagnóstico Pré-Implantação/métodos
7.
J Environ Manage ; 302(Pt A): 113974, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34710764

RESUMO

In the context of carbon neutrality and the National Economic Circle Strategy, understanding regional disparities in carbon emissions from household consumption is conducive to regional coordination as well as high-quality and low-carbon development in China. In this study, a multiregional input-output (MRIO) model and structural decomposition analysis (SDA) are adopted to investigate the regional disparity change trends of embedded carbon emissions (ECEs) from urban households and the underlying drivers during the rapid economic development period from 2002 to 2012 in China. The results indicate that the eastern regions tended to have larger increments in total urban household ECEs, while the western regions tended to have faster growth rates. An increasing disparity and evident outsourcing pattern can be observed during the study period. The consumption level had a strong positive effect on urban household ECEs in all of the provinces, while the carbon efficiency, consumption pattern, production structure, and population size had differentiated offsetting effects on urban household ECEs in various provinces. The results obtained in this study are conducive to promoting joint efforts for carbon emission reduction and narrowing regional disparities.


Assuntos
Carbono , Serviços Terceirizados , Carbono/análise , Dióxido de Carbono/análise , China , Desenvolvimento Econômico
8.
Ecotoxicol Environ Saf ; 225: 112742, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34500386

RESUMO

Degradation of norfloxacin (NFX) by zinc oxide (ZnO)/g-C3N4, a magnetic sheet ZnO with g-C3N4 on its surface was studied. Through a new preparation system method, hydrothermal reaction provides a solid-layered magnetic ZnO material basis, and the simple thermal condensation method was used to transform the urea into g-C3N4 on the magnetic sheet ZnO in a uniform and orderly manner to increase the stability and photocatalytic performance of the material. Compared with previous studies, the pore volume and photocatalytic performance of the material are improved, and became more stable. By studying the degradation effect of basic and photocatalytic materials prepared in different proportions, the kinetic constant of ZGF is 0.01446 (min-1). The response surface methodology (RSM) was used to study the optimization and effect of solution pH (4-12), photocatalyst concentration (0.2-1.8 g/L), and NFX concentration (3-15 mg/L) on the degradation rate of NFX during photocatalytic degradation. The R2 value of the RSM model was 0.9656. The NFX removal rate is higher than 90% when the amount of catalyst is 1.43 g/L, the solution pH is 7.12, and the NFX concentration is less than 8.61 mg/L. After 5 cycles, the degradation rate of magnetic materials decreased to 92.8% of the first time. The capture experiment showed that the photocatalytic machine Toxicities was mainly hole action. The TOC removal rate within 2 h was 30%, a special intermediate toxicity analysis method was adopted according to the characteristics of NFX's inhibitory effect on Escherichia coli community. The toxicity of degraded NFX solution disappeared, and the possibility of non-toxic harm of by-products was verified. LC-Q-TOF method was used to detect and analyze various intermediate products converted from NFX after photocatalytic degradation, and the photocatalytic degradation pathway of NFX was proposed.


Assuntos
Óxido de Zinco , Catálise , Escherichia coli , Cinética , Luz , Norfloxacino/toxicidade , Óxido de Zinco/toxicidade
9.
J Environ Manage ; 295: 113051, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34182342

RESUMO

Haze pollution not only negatively influences public health but also causes great economic losses. However, most previous studies have mainly focused on health-related economic losses, while the negative effects of haze pollution on the tourism industry are often ignored, leading to the unsustainable development of tourism. In this context, contrasting with previous research perspectives, this article selected several representative tourist cities from East China, South China, Central China, North China, Northwest China, Southwest China, and Northeast China as research objects in an empirical study, developing an economic loss analysis system to quantitatively evaluate the losses in the tourism industry caused by haze pollution. This system uses the satin bower bird optimization-based distribution estimation method to identify the optimal distribution of haze pollution, demonstrating superior performance to the traditional estimation method. Meanwhile, the optimal distribution of haze pollution is employed to measure the probability of different concentration limits in each area. Furthermore, the economic loss formula of the tourism industry is proposed in the devised system, calculating the economic loss caused by haze pollution at different degrees. The results show that haze pollution in different degrees has caused varying degrees of losses to China's tourism industry. In terms of seasonality and regionality, different seasons and different regions produce different results. Compared with summer, autumn and winter haze pollution is more severe, creating obvious seasonal differences. There is also a regional agglomeration effect, whereby the regional distribution of haze pollution is consistent with each region's economic development.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , China , Cidades , Monitoramento Ambiental , Poluição Ambiental/análise , Material Particulado/análise , Turismo
10.
Taiwan J Obstet Gynecol ; 60(2): 225-231, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33678320

RESUMO

OBJECTIVE: This study aimed to investigate the outcomes of patients who had preimplantation genetic testing for chromosomal structural rearrangement (PGT-SR) or for aneuploidy screening (PGT-A) with different indications. METHODS: This was a retrospective study at a single center. Pregnancy outcomes of all couples who had PGT from 2014 to 2018 were retrospectively analyzed, and the cumulative pregnancy rates (CPR) and the cumulative live birth/ongoing pregnancy rate (CLB/OPR) per patient with at least one transfer cycle were calculated. RESULTS: A total of 313 PGT-SR cycles of 255 patients, 22 PGT-sexing cycles of 20 patients, and 190 PGT-A cycles of 168 patients were performed during the period. In PGT-SR, the overall CPR and the CLB/OPR were 68.04% and 59.79%, respectively. In PGT-A, the CPR and CLB/OPR were 67.52% and 58.12%, respectively. We also found that the CPR (93.75%) and CLB/OPR (87.50%) were highest in patients for PGT-sexing with a diagnosis of Y chromosomal microdeletion. In addition, we discovered a significant trend that aneuploidy rate significantly increased with maternal age (p = 0.000) in PGT-A population. No significant difference was found in the mosaicism rate or clinical outcomes among the age groups. Similarly, the significance was absent in the PGT-SR population. CONCLUSION: We reviewed the CPR and CLB/OPR for different indications since the 24-chromosome technique has been applied in the clinical setting for 4 years in our center. We hope that our results will provide some pointed guidance and a new perspective on outcomes for PGT in certain patients and clinicians.


Assuntos
Transferência Embrionária/estatística & dados numéricos , Testes Genéticos/estatística & dados numéricos , Nascido Vivo , Taxa de Gravidez , Diagnóstico Pré-Implantação/estatística & dados numéricos , Adulto , Aneuploidia , Feminino , Testes Genéticos/métodos , Humanos , Gravidez , Diagnóstico Pré-Implantação/métodos , Estudos Retrospectivos , Aberrações dos Cromossomos Sexuais/embriologia , Adulto Jovem
11.
Biomed Environ Sci ; 33(5): 374-383, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32553083

RESUMO

OBJECTIVE: Allocation of human resources to address inequalities in the public health system has increasingly attracted societal and political attention. Using the Centers for Disease Control and Prevention (CDCs) system of China as an example, we evaluated inequality in the public health workforce distribution across different regions in China between 2008 and 2017, with the aim of providing information for policymakers to support resource allocation and address growing health inequities. METHODS: We used three standard public health workforce inequality indices - Gini coefficient, Theil L, and Theil T - and spatial autocorrelation analysis to explore spatial clusters of the workforce in different provinces, visualized with geographical tools. RESULTS: The aggregate workforce-to-population ratio decreased from 1.47 to 1.42 per 10,000 population from 2008 to 2017, and was consistently lower than the National Health Commission's (NHC) recommended critical shortage threshold of 1.75. The workforce distribution inequality indices varied by regional socioeconomic and health system development. Geographic clustering of CDCs workforce distribution was evident, with H-H and L-L clusters in western China and the Guangdong-Fujian region, respectively. CONCLUSIONS: Our study addressed key issues for government and policymakers in allocation of public health human resources. There is an urgent need for careful identification of analytic questions that will help carry out public health functions in the new era, alongside policy implications for an equitable distribution of the public health workforce focusing on the western region and low-low cluster areas.


Assuntos
Mão de Obra em Saúde/estatística & dados numéricos , Saúde Pública/estatística & dados numéricos , Fatores Socioeconômicos , China
12.
Sci Total Environ ; 706: 135735, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31806313

RESUMO

Chinese coal-fired power plants (CFPPs) are experiencing large-scale and rapid retrofitting of ultralow emission (ULE), causing significant changes in emission level of particulate matter (PM) from CFPPs. In this study, based on coal ash mass balance over the whole process, an integrated emission factors (EFs) database of three size-fractioned particulate matters (PM2.5, PM10, and PMtotal) for CFPPs is constructed, which covers almost all typical ULE technical routes installed in CFPPs. To verify the reliability of PM EFs established in this study, we compare those with related results based on field tests. Overall, the gaps in the EFs of PM2.5, PM10, and PMtotal obtained by the two methods are not outrageous within a reasonable range. By combined with the refined size-fractioned PM EFs and unit-based activity level database, a detailed high-resolution emission inventory of PM2.5, PM10, and PMtotal from Chinese CFPPs in 2017 is established, with the corresponding total emissions of 143, 207, and 267 kt, respectively. Our estimation of PMtotal emission is comparable to the official statistics announced by China Electricity Council (CEC), which further demonstrates the reliability of PM EFs constructed in this study. Moreover, potential reductions of PM from CFPPs at two stages before and after 2017 are assessed under three application scenarios of major ULE technical routes. We forecast the final annual emissions of PM2.5, PM10, and PMtotal until 2020 will be reduced further, which fall within the range of 86-111 kt, 120-157 kt, and 142-184 kt, respectively, if all CFPPs achieve ULE requirements under the three scenarios. We believe our integrated database of PM EFs of CFPPs has good universality, and the forecast results will be helpful for policy guidance of ULE technologies, emissions inventory compilation, and regional air quality simulation and management.

13.
Beijing Da Xue Xue Bao Yi Xue Ban ; 47(5): 781-6, 2015 Oct 18.
Artigo em Chinês | MEDLINE | ID: mdl-26474615

RESUMO

OBJECTIVE: To verify the fracture risk assessment tool (FRAX) to estimate the probability of osteoporotic fracture in patients with rheumatoid arthritis (RA) with or without bone mineral density (BMD), and identify associated risk factors of osteoporosis. METHODS: In the study, 200 patients with rheumatoid arthritis aged more than 40 years in Peking University First Hospital from Dec. 2009 to Dec. 2012 were recruited. Clinical information was obtained from a questionnaire of their case history and medical records. FRAX tool was administered. Their lumber spine and left femoral BMD were determined by dual energy X ray absorptiometry. The gender, age, disease duration, menopause status, body mass index (BMI) and accumulative dose of glucocorticoid were obtained in retrospect. Correlation analysis was conducted between the BMD and clinical information. RESULTS: The study population (female, 77.5%) had a mean age of 59.4 years, in which 10 (13%) patients showed a normal BMD, 67 (87%) were osteopenia or osteoporosis, while 32 patients (16%) had fragile fracture. Compared with the patients with normal BMD, the subjects with low BMD had significantly older age, longer period for corticoids usage, higher day dose and accumulated dose of corticoids.The 10-year fracture risk of sustaining major osteoporotic fractures and hip fracture was higher. No significant difference was observed between the 10-year fracture risks calculated with BMD and without BMD. The values of the different area under the receiver operating characteristic (ROC) curve (AUC) for major and hip fractures calculated in three ways: without BMD, with the femoral neck BMD, and with T-score. The best result was for FRAX tool for hip fracture with the T-score (AUC 0.899). A stepwise multivariate linear regression model was constructed to explore the relationship between the different clinical factors studied and a low BMD. Three statistically significant variables for lumber BMD were pain on visual assessment scale (VAS) (P=0.02), fracture history (P=0.003) and a higher steroid accumulated dose (P=0.008). Three statistically significant variables for left hip BMD were age (P<0.001), fracture history (P=0.05) and lower BMI (P=0.03). CONCLUSION: Low BMD is a common complication in RA patients. Risk factors for major fracture and hip fracture are increased. There is a positive correlation between FRAX calculated with and without BMD or T score. FRAX with the femoral neck T score or BMD presents a discriminatory capacity better than FRAX without BMD, according to the AUC ROC.


Assuntos
Artrite Reumatoide/fisiopatologia , Densidade Óssea , Fraturas por Osteoporose/complicações , Medição de Risco , Absorciometria de Fóton , Artrite Reumatoide/complicações , Pequim , Índice de Massa Corporal , Feminino , Fraturas do Quadril/complicações , Humanos , Pessoa de Meia-Idade , Osteoporose/complicações , Curva ROC , Fatores de Risco
14.
Math Biosci ; 264: 101-7, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25843352

RESUMO

Through theoretical analysis of the statistics of stochastic calcium (Ca(2+)) release (i.e., the amplitude, duration and inter-event interval of simulated Ca(2+) puffs and sparks), we show that a Langevin description of the collective gating of Ca(2+) channels may be a good approximation to the corresponding Markov chain model when the number of Ca(2+) channels per Ca(2+) release unit (CaRU) is in the physiological range. The Langevin description of stochastic Ca(2+) release facilitates our investigation of correlations between successive puff/spark amplitudes, durations and inter-spark intervals, and how such puff/spark statistics depend on the number of channels per release site and the kinetics of Ca(2+)-mediated inactivation of open channels. When Ca(2+) inactivation/de-inactivation rates are intermediate-i.e., the termination of Ca(2+) puff/sparks is caused by an increase in the number of inactivated channels-the correlation between successive puff/spark amplitudes is negative, while the correlations between puff/spark amplitudes and the duration of the preceding or subsequent inter-spark interval are positive. These correlations are significantly reduced or change signs when inactivation/de-inactivation rates are extreme (slow or fast) and puff/sparks terminate via stochastic attrition.


Assuntos
Canais de Cálcio/fisiologia , Sinalização do Cálcio/fisiologia , Cadeias de Markov , Modelos Teóricos , Animais
15.
Am J Physiol Heart Circ Physiol ; 308(5): H510-23, 2015 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-25485896

RESUMO

Population density approaches to modeling local control of Ca(2+)-induced Ca(2+) release in cardiac myocytes can be used to construct minimal whole cell models that accurately represent heterogeneous local Ca(2+) signals. Unfortunately, the computational complexity of such "local/global" whole cell models scales with the number of Ca(2+) release unit (CaRU) states, which is a rapidly increasing function of the number of ryanodine receptors (RyRs) per CaRU. Here we present an alternative approach based on a Langevin description of the collective gating of RyRs coupled by local Ca(2+) concentration ([Ca(2+)]). The computational efficiency of this approach no longer depends on the number of RyRs per CaRU. When the RyR model is minimal, Langevin equations may be replaced by a single Fokker-Planck equation, yielding an extremely compact and efficient local/global whole cell model that reproduces and helps interpret recent experiments that investigate Ca(2+) homeostasis in permeabilized ventricular myocytes. Our calculations show that elevated myoplasmic [Ca(2+)] promotes elevated network sarcoplasmic reticulum (SR) [Ca(2+)] via SR Ca(2+)-ATPase-mediated Ca(2+) uptake. However, elevated myoplasmic [Ca(2+)] may also activate RyRs and promote stochastic SR Ca(2+) release, which can in turn decrease SR [Ca(2+)]. Increasing myoplasmic [Ca(2+)] results in an exponential increase in spark-mediated release and a linear increase in nonspark-mediated release, consistent with recent experiments. The model exhibits two steady-state release fluxes for the same network SR [Ca(2+)] depending on whether myoplasmic [Ca(2+)] is low or high. In the later case, spontaneous release decreases SR [Ca(2+)] in a manner that maintains robust Ca(2+) sparks.


Assuntos
Sinalização do Cálcio , Ventrículos do Coração/metabolismo , Modelos Cardiovasculares , Miócitos Cardíacos/metabolismo , Animais , Cálcio/metabolismo , Ventrículos do Coração/citologia , Homeostase , Cadeias de Markov , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Retículo Sarcoplasmático/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo
16.
Org Biomol Chem ; 10(4): 724-8, 2012 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-22167248

RESUMO

A simple and novel protocol for the efficient synthesis of a series of 8-carboxylnaphthyl functionalized pyrazolo[3,4-b]pyridine derivatives was developed through a one-pot, three-component reaction involving acenaphthylene-1,2-dione and 1H-pyrazol-5-amine in acetic acid medium. The reaction represents the first facile conversion of acenaphthenequinone to naphthoic acid via C-C bond cleavage without need for multi-step transformation.


Assuntos
Técnicas de Química Sintética/métodos , Pirazóis/química , Piridinas/química , Acenaftenos/síntese química , Acenaftenos/química , Técnicas de Química Sintética/economia , Pirazóis/síntese química , Piridinas/síntese química
17.
Zhonghua Yu Fang Yi Xue Za Zhi ; 44(8): 717-20, 2010 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-21055022

RESUMO

OBJECTIVE: To perform cost-effectiveness analysis of interventions in female sex workers in Dehong prefecture in China, with an aim of providing evidence for rational resource allocation in female sex worker interventions in the future. METHODS: The data of expenses for female sex worker interventions in Dehong from 2005 - 2007 were obtained through questionnaire survey. Meanwhile, the data from baseline survey in 2004, from surveillance of female sex workers from 2005 through 2007 as well as from the special survey on sexual transmission in 2007 were collected. Intervention effectiveness was estimated by using SEX 2.0 Tool recommended by UNAIDS. The cost-effectiveness ratio is calculated as the total cost divided by the number of estimated non-HIV patients due to these interventions. RESULTS: The total cost for female sex worker interventions is 916 400 RMB from 2005 through 2007, and a total of 3297 female sex workers were effectively intervened in these three years. Thus, the actual intervention cost for each female sex worker (unit cost) is 277.9 RMB. If all the intervention work is performed as required, the predicted unit cost for female sex worker intervention would be 500.5 RMB. During the period of 2005 through 2007, 69 female sex workers had been successfully prevented from HIV infection; therefore, the cost-effectiveness ratio is 13 282 RMB. CONCLUSION: Intervention among female sex workers is highly cost-effective.


Assuntos
Infecções por HIV/prevenção & controle , Modelos Estatísticos , Prevenção Primária/economia , Trabalho Sexual , China , Análise Custo-Benefício , Feminino , Infecções por HIV/economia , Infecções por HIV/epidemiologia , Humanos
18.
Zhonghua Yu Fang Yi Xue Za Zhi ; 42(12): 888-91, 2008 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-19141222

RESUMO

OBJECTIVE: To provide evidence for resource allocation and cooperation between domestic and international HIV/AIDS programs in China by analyzing the needs and current levels of resource input in provinces. METHODS: National and provincial international cooperation program investment and allocation data from 2000 to 2006 were collected. Several factors in each province were analyzed through multiple regression analysis in order to determine whether they had a statistical correlation to the distribution of international HIV/AIDS program resources in China, including: the Gross Domestic Product (GDP), the number of accumulated people living with HIV/AIDS, and the number of accumulated people living with AIDS. Then the Z values were calculated at each provincial level and compared with related international investment. The resource allocation in different program areas were compared with the level of resource input by international and central government HIV/AIDS prevention and control programs through Chi-square test. RESULTS: The international cooperation program investment at local level from 2000 to 2006 were 4893, 24 669, 50 567, 52 950, 112 143, 363 396 and 247 045 thousand RMB respectively, and at national level were 3007, 19 726, 29 035, 37 530, 77 500, 105 786 and 77 035 thousand RMB respectively. There was a statistical correlation between international HIV/AIDS program resource input and the accumulated number of people living with AIDS (R is 0.56 and 0.69 accordingly, and P < 0.01 both). However, there was no statistical correlation between international resource input and the GDP of each province. International HIV/AIDS cooperation programs did not invest in each province according to its practical needs (R = 0.066, P = 0.725). The international cooperation program investments and needs in different province could not meet completely. The ranks of Z value in Guangdong, Shandong and Jiangsu were 3, 5 and 6, but the ranks of international cooperation program in those provinces were 18, 13 and 28 respectively. The investment proportion for national investment in surveillance and testing, advocacy education and intervention, care and support, and others were 22.4%, 19.7%, 36.8% and 21.1% respectively in 2005, and for international cooperation program were 11.5%, 20.8%, 10.4% and 57.4%. For national investment in 2006 were 18.6%, 23.8%, 32.6% and 25.0%, and international cooperation program were 14.0%, 34.3%, 17.1% and 34.6% respectively. The Chinese government and international programs therefore had different priorities in 2005 (chi(2) = 35.09, P < 0.01) and 2006 (chi(2) = 9.26, P = 0.026). CONCLUSIONS: International HIV/AIDS cooperation programs should be better integrated with national programs and combined with epidemic situation and GDP to decide the amount and areas of the investment in order to ensure that they supplement Chinese HIV/AIDS prevention and control activities effectively. The advantages that can be gained from technical support provided by international programs should be further emphasized in line with China's HIV/AIDS prevention and control priorities.


Assuntos
Síndrome da Imunodeficiência Adquirida/economia , Cooperação Internacional , Alocação de Recursos , Síndrome da Imunodeficiência Adquirida/prevenção & controle , China , Humanos
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