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This article presents a dual-wavelength signal wave output system capable of generating a broad range of adjustable wavelength intervals. The setup involved the creation of a dual-wavelength cascaded Raman laser featuring composite cavities operating at 1176â nm and 1313â nm. Experimental investigations were carried out on an external cavity MgO:PPLN-OPO driven by the cascaded Raman laser. By setting the crystal polarization period to 27.6-34.4â µm and the temperature to 50-130°C, adjustable tunable output of dual-wavelength signal wave at 1176â nm-MgO:PPLN-OPO (1550-2294â nm) and 1313â nm-MgO:PPLN-OPO (1768-2189â nm) was achieved with a wavelength interval of 0-218â nm. Under the conditions of a period of 34.4â µm, temperature of 90°C, and an incident Raman power of 2.6 W, the highest conversion efficiency of Raman to dual-wavelength signal wave (2212, 2182â nm) was 34.2%. Furthermore, the maximum output power of dual-wavelength signal wave was recorded at 1.02 W with an incident Raman power of 3.33 W.
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The Tigris and Euphrates River Basin is an important water supply, but it suffers from water scarcity. It is necessary to carry out reasonable allocation of water resources in this region. Since water resources issues in this region are of multinational interest, international cooperative distribution efforts are needed. Common water resources allocation modes include equal allocation, demand priority or negotiation allocation. In order to derive the applicable range of various water resources allocation modes, this article constructs three differential game models and compares and analyzes the equilibrium results obtained by the models. Finally, the study shows that when the cost of developing water resources is small and the revenue obtained from developing water resources is large, the water-scarce region can obtain the maximum benefit by adopting the demand priority mode. Otherwise, the water-scarce region can obtain the maximum benefit by adopting the negotiation allocation mode. This study can inform the allocation, strategic interaction and cooperation of dynamic water resources in the two river basins.
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The invasive black tiger shrimp has caused serious ecological problems in the America. However, since it can be directly eaten or made into feed, it may be beneficial to other countries. In order to ensure ecological security, it is necessary to control the invasion of the black tiger shrimp through international cooperation. Common control modes of the black tiger shrimp include the introducing natural enemy mode, making feed mode and the "bringing to the table" mode. In order to derive the applicable scope of various control modes of the black tiger shrimp and provide suggestions for the security and sustainability of the ecological supply chain of the America and cooperative country, this article constructs three differential game models and compares and analyzes the equilibrium results obtained by the models. Finally, the study shows that the higher the price of feed and the price of black tiger shrimp, the greater the degree of control of the black tiger shrimp. If the price of the black tiger shrimp and the reputation of the America for controlling the black tiger shrimp are lower, the America can gain more benefits under the feed production mode. Otherwise, the America prefers to sell the black tiger shrimp directly, thus directly "bringing to the table". Compared with the feed production or "bringing to the table" mode, cooperative country prefer to control the black tiger shrimp flooding through the natural enemy introduction mode.
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Cooperación Internacional , Especies Introducidas , Animales , PenaeidaeRESUMEN
In 2020, COVID-19 became a global pandemic. Older people are less resistant to the novel coronavirus. In order to ensure the health of the elderly population, the governments of five Central Asian countries should provide home medical services for the elderly or provide "green channel" to medical services. This "green channel" means providing a special service and treatment for the elderly in the hospital to ensure that they can safely and easily access the medical services they need. In order to study the application scope of various modes, this article constructs three modes of differential game: no special care, home medical care and "green channel". And the equilibrium results are compared and analyzed. Research shows that when the additional medical costs associated with house calls or "green channel" gradually increase, the social benefits to both the elderly and the government gradually decrease, and eventually it is less than the social benefits under the no-special care model. The greater the credibility of the government under the "green channel" service model, the greater the social benefits of the government. However, the greater the credibility of the government under the home medical service model, the smaller the social benefits of the government.
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COVID-19 , Servicios de Atención de Salud a Domicilio , Humanos , Anciano , COVID-19/epidemiología , Asia , Hospitales , GobiernoRESUMEN
As the mental health problems of young employees become more and more prominent, the government and labor unions need to take measures to protect the mental health of young employees. Considering that the main mental health safeguard measures are divided into psychological screening, providing social security and strengthening training, this article constructs a differential game model under these three modes. The balanced efforts and social benefits of the government and labor unions under the three modes are obtained, and the applicable conditions of various mental health protection modes are compared. The results show that if the government pays a lower cost, the government gets the highest economic benefit under the training mode, followed by the security mode, and the government gets the lowest economic benefit under the psychological screening mode. If the reputation of the labor unions improved by its efforts is low, the equilibrium benefits of the labor unions under psychological screening and providing security are the same, and greater than the equilibrium benefits under the intensive training mode. If the labor unions have a higher reputation enhanced by its efforts, the balance return of the labor unions under the guarantee mode is the highest, followed by the balance return under the intensive training mode, and the balance return of the labor unions under the psychological screening mode is the lowest.
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Salud Mental , Seguridad Social , Humanos , Sindicatos , GobiernoRESUMEN
Forest fires have a great impact on the ecological environment. The government needs to take measures to control forest fires. Forest fires are easily affected by wind speed and other weather conditions, and the difficulty of extinguishing forest fires is easily affected by terrain complexity. Effective management methods can protect the important ecological functions of forests, thereby maintaining long-term development and economic efficiency. The government can put out the fire by remote monitoring, personnel extinguishing and helicopter extinguishing. Different from most articles on how to eliminate forest fires from the technical point of view, this article mainly analyzes from the two aspects of optimizing resource allocation and guiding policy formulation. This article constructs the differential game model under these three modes, and then obtains the equilibrium result. And the comparative analysis. Finally, the conclusion is drawn. The stronger the wind, the more residents need to flee. However, strong winds are not conducive to crews and helicopters fighting the fire. Rather than fighting fires, residents are more inclined to detect forest fires in time through remote monitoring. When the personnel can effectively control the fire, the personnel fire extinguishing mode is preferentially selected. Otherwise, helicopter firefighting mode should be selected.
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Incendios , Incendios Forestales , Bosques , Incendios/prevención & control , Tiempo (Meteorología) , Viento , ÁrbolesRESUMEN
In 2020, COVID-19 became a global pandemic. The Chinese government's quarantine measures tend to cause anxiety, tension and depression among the quarantined people. This article constructs a differential game model of self-regulation, government guidance and social forces guidance. Then, the psychological benefits of the masses and the benefits of the whole society under the three modes are obtained, and the applicable conditions of various connection modes are compared. The research results show that: compared with social power channeling, the public under the government channeling mode can obtain more psychological benefits. However, with the increase of guidance, the difference between the psychological benefits of different ways of guidance first decreases and then tends to be stable. Under the guidance mode, the social benefits of the government decrease, and the more guidance, the smaller the social benefits. Therefore, both the government and social forces should make use of limited resources to conduct appropriate psychological counseling for the isolated population.
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In recent years, interest in family-to-work interference and its consequences has increased dramatically. Drawing on conservation of resources theory, we propose and test a dual spillover spiraling model which examines the indirect effects of family incivility on workplace interpersonal deviance through increasing family-to-work conflict (resource loss spiral) and decreasing family-to-work enrichment (resource gain spiral). We also examine the moderating effects of family-supportive supervisor behaviors on these indirect effects. The findings from a three-wave survey, with 455 employees and their coworkers in 60 teams, reveal that experienced family incivility (Time 1) induces more interpersonal deviance at work (Time 3) through facilitating family-to-work conflict (Time 2) and inhibiting family-to-work enrichment (Time 2). Such indirect deviation amplifying effects are mitigated by higher supervisor-level family-supportive supervisor behaviors (Time 1). Theoretical and practical implications are discussed.
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A multitude of disease and therapy related factors drive the frequent development of kidney disorders in cancer patients. Along with chemotherapy, the newer targeted therapeutics can also cause kidney dysfunction through on and off-target mechanisms. Interestingly, among the small molecule inhibitors approved for the treatment of cancers that harbor BRAF-kinase activating mutations, vemurafenib can trigger tubular damage and acute kidney injury. BRAF is a proto-oncogene involved in cell growth. To investigate the underlying mechanisms, we developed cell culture and mouse models of vemurafenib kidney toxicity. At clinically relevant concentrations vemurafenib induces cell-death in transformed and primary mouse and human kidney tubular epithelial cells. In mice, two weeks of daily vemurafenib treatment causes moderate acute kidney injury with histopathological characteristics of kidney tubular epithelial cells injury. Importantly, kidney tubular epithelial cell-specific BRAF gene deletion did not influence kidney function under normal conditions or alter the severity of vemurafenib-associated kidney impairment. Instead, we found that inhibition of ferrochelatase, an enzyme involved in heme biosynthesis contributes to vemurafenib kidney toxicity. Ferrochelatase overexpression protected kidney tubular epithelial cells and conversely ferrochelatase knockdown increased the sensitivity to vemurafenib-induced kidney toxicity. Thus, our studies suggest that vemurafenib-associated kidney tubular epithelial cell dysfunction and kidney toxicity is BRAF-independent and caused, in part, by off-target ferrochelatase inhibition.
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Ferroquelatasa , Proteínas Proto-Oncogénicas B-raf , Animales , Línea Celular Tumoral , Resistencia a Antineoplásicos , Humanos , Indoles/toxicidad , Riñón/metabolismo , Ratones , Mutación , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas B-raf/metabolismo , Sulfonamidas/toxicidad , VemurafenibRESUMEN
Acute kidney injury (AKI) is a common clinical syndrome associated with adverse short- and long-term sequelae. Renal tubular epithelial cell (RTEC) dysfunction and cell death are among the key pathological features of AKI. Diverse systemic and localized stress conditions such as sepsis, rhabdomyolysis, cardiac surgery, and nephrotoxic drugs can trigger RTEC dysfunction. Through an unbiased RNA inhibition screen, we recently identified cyclin-dependent kinase-like 5 (Cdkl5), also known as serine/threonine kinase-9, as a critical regulator of RTEC dysfunction associated with nephrotoxic and ischemia-associated AKI. In the present study, we examined the role of Cdkl5 in rhabdomyolysis-associated AKI. Using activation-specific antibodies and kinase assays, we found that Cdkl5 is activated in RTECs early during the development of rhabdomyolysis-associated AKI. Furthermore, we found that RTEC-specific Cdkl5 gene ablation mitigates rhabdomyolysis-associated renal impairment. In addition, the small-molecule kinase inhibitor AST-487 alleviated rhabdomyolysis-associated AKI in a Cdkl5-dependent manner. Mechanistically, we demonstrated that Cdkl5 phosphorylates the transcriptional regulator sex-determining region Y box 9 (Sox9) and suppresses its protective function under stress conditions. On the basis of these results, we propose that, by suppressing the protective Sox9-directed transcriptional program, Cdkl5 contributes to rhabdomyolysis-associated renal impairment. All together, the present study identified Cdkl5 as a critical stress-induced kinase that drives RTEC dysfunction and kidney injury linked with distinct etiologies.
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Lesión Renal Aguda/metabolismo , Células Epiteliales/metabolismo , Túbulos Renales/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Factor de Transcripción SOX9/metabolismo , Lesión Renal Aguda/patología , Muerte Celular/fisiología , Humanos , Riñón/metabolismo , Fosforilación , Rabdomiólisis/inducido químicamente , Transducción de Señal/fisiologíaRESUMEN
Acute kidney injury (AKI) is a common clinical condition associated with diverse etiologies and abrupt loss of renal function. In patients with sepsis, rhabdomyolysis, cancer, and cardiovascular disorders, the underlying disease or associated therapeutic interventions can cause hypoxia, cytotoxicity, and inflammatory insults to renal tubular epithelial cells (RTECs), resulting in the onset of AKI. To uncover stress-responsive disease-modifying genes, here we have carried out renal transcriptome profiling in three distinct murine models of AKI. We find that Vgf nerve growth factor inducible gene up-regulation is a common transcriptional stress response in RTECs to ischemia-, cisplatin-, and rhabdomyolysis-associated renal injury. The Vgf gene encodes a secretory peptide precursor protein that has critical neuroendocrine functions; however, its role in the kidneys remains unknown. Our functional studies show that RTEC-specific Vgf gene ablation exacerbates ischemia-, cisplatin-, and rhabdomyolysis-associated AKI in vivo and cisplatin-induced RTEC cell death in vitro Importantly, aggravation of cisplatin-induced renal injury caused by Vgf gene ablation is partly reversed by TLQP-21, a Vgf-derived peptide. Finally, in vitro and in vivo mechanistic studies showed that injury-induced Vgf up-regulation in RTECs is driven by the transcriptional regulator Sox9. These findings reveal a crucial downstream target of the Sox9-directed transcriptional program and identify Vgf as a stress-responsive protective gene in kidney tubular epithelial cells.
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Lesión Renal Aguda/metabolismo , Células Epiteliales/metabolismo , Túbulos Renales/metabolismo , Factores de Crecimiento Nervioso/biosíntesis , Factor de Transcripción SOX9/metabolismo , Regulación hacia Arriba , Lesión Renal Aguda/inducido químicamente , Lesión Renal Aguda/genética , Lesión Renal Aguda/patología , Animales , Células Epiteliales/patología , Túbulos Renales/patología , Ratones , Ratones Transgénicos , Factores de Crecimiento Nervioso/genética , Factor de Transcripción SOX9/genéticaRESUMEN
Renal tubular epithelial cells (RTECs) perform the essential function of maintaining the constancy of body fluid composition and volume. Toxic, inflammatory, or hypoxic-insults to RTECs can cause systemic fluid imbalance, electrolyte abnormalities and metabolic waste accumulation- manifesting as acute kidney injury (AKI), a common disorder associated with adverse long-term sequelae and high mortality. Here we report the results of a kinome-wide RNAi screen for cellular pathways involved in AKI-associated RTEC-dysfunction and cell death. Our screen and validation studies reveal an essential role of Cdkl5-kinase in RTEC cell death. In mouse models, genetic or pharmacological Cdkl5 inhibition mitigates nephrotoxic and ischemia-associated AKI. We propose that Cdkl5 is a stress-responsive kinase that promotes renal injury in part through phosphorylation-dependent suppression of pro-survival transcription regulator Sox9. These findings reveal a surprising non-neuronal function of Cdkl5, identify a pathogenic Cdkl5-Sox9 axis in epithelial cell-death, and support CDKL5 antagonism as a therapeutic approach for AKI.
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Lesión Renal Aguda/metabolismo , Células Epiteliales/citología , Proteínas Serina-Treonina Quinasas/metabolismo , Factor de Transcripción SOX9/metabolismo , Animales , Muerte Celular , Células Epiteliales/metabolismo , Femenino , Proteínas Fluorescentes Verdes/metabolismo , Humanos , Queratinocitos/metabolismo , Riñón/metabolismo , Túbulos Renales/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neuronas/metabolismo , Interferencia de ARN , ARN Interferente Pequeño/metabolismoRESUMEN
Aberrant cell cycle activation is a hallmark of carcinogenesis. Recently three cell cycle targeting cyclin-dependent kinase 4/6 (CDK4/6) inhibitors have been approved for the treatment of metastatic breast cancer. CDK4/6 inhibitors suppress proliferation through inhibition of CDK4/6-dependent retinoblastoma-1 (Rb1) phosphorylation and inactivation, a key regulatory step in G1-to-S-phase transition. Importantly, aberrant cell cycle activation is also linked with several non-oncological diseases including acute kidney injury (AKI). AKI is a common disorder caused by toxic, inflammatory, and ischemic damage to renal tubular epithelial cells (RTECs). Interestingly, AKI triggered by the anti-cancer drug cisplatin can be mitigated by ribociclib, a CDK4/6 inhibitor, through mechanisms that remain unclear. Employing in vivo cell cycle analysis and functional Rb1 knock-down, here, we have examined the cellular and pharmacological basis of the renal protective effects of ribociclib during cisplatin nephrotoxicity. Remarkably, siRNA-mediated Rb1 silencing or RTEC-specific Rb1 gene ablation did not alter the severity of cisplatin-associated AKI; however, it completely abrogated the protective effects conferred by ribociclib administration. Furthermore, we find that cisplatin treatment evokes CDK4/6 activation and Rb1 phosphorylation in the normally quiescent RTECs, however, this is not followed by S-phase entry likely due to DNA-damage induced G1 arrest. The cytoprotective effects of ribociclib are thus not a result of suppression of S-phase entry but are likely dependent on the maintenance of Rb1 in a hypo-phosphorylated and functionally active form under stress conditions. These findings delineate the role of Rb1 in AKI and illustrate the pharmacological basis of the renal protective effects of CDK4/6 inhibitors.
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Lesión Renal Aguda/inducido químicamente , Lesión Renal Aguda/tratamiento farmacológico , Aminopiridinas/uso terapéutico , Cisplatino/farmacología , Sustancias Protectoras/uso terapéutico , Purinas/uso terapéutico , Proteínas de Unión a Retinoblastoma/metabolismo , Lesión Renal Aguda/metabolismo , Aminopiridinas/farmacología , Animales , Puntos de Control del Ciclo Celular/efectos de los fármacos , Células Cultivadas , Quinasa 4 Dependiente de la Ciclina/antagonistas & inhibidores , Quinasa 4 Dependiente de la Ciclina/metabolismo , Quinasa 6 Dependiente de la Ciclina/antagonistas & inhibidores , Quinasa 6 Dependiente de la Ciclina/metabolismo , Citoprotección , Daño del ADN/efectos de los fármacos , Modelos Animales de Enfermedad , Células Epiteliales/metabolismo , Técnicas de Silenciamiento del Gen , Túbulos Renales/patología , Masculino , Ratones , Ratones Noqueados , Fosforilación/efectos de los fármacos , Sustancias Protectoras/farmacología , Purinas/farmacología , Proteínas de Unión a Retinoblastoma/genética , Transducción de Señal/efectos de los fármacosRESUMEN
An end-pumped actively $Q$Q-switched ${\rm Nd}\!:\!{{\rm YVO}_4}/{{\rm YVO}_4}$Nd:YVO4/YVO4 Raman laser with a folded coupled cavity is demonstrated to study the evolution of Raman beam quality. The theoretical mechanism of the beam cleanup effect of stimulated Raman scattering is analyzed. The beam quality ($M^2$M2) of the Raman beam and the fundamental beams before and after the Raman conversion are measured experimentally. The results show that with the incident pump power increasing, the ${M^2}$M2 of the fundamental beam increases from 1.85 to 3.08, while the ${M^2}$M2 of the Raman beam increases from 1.21 to 1.69. The beam quality of the Raman laser and its degradation are better than that of the fundamental laser.
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We report herein an efficient actively Q-switched Nd:YVO4/YVO4 intracavity Raman laser operating at 1176 nm. Factors such as resonator geometry and pumping scheme are optimized to strengthen the power scalability and the conversion efficiency of the intracavity Raman laser. With a folded coupled cavity adopted to make full use of the high pump intensity on the Raman crystal, the first-order Stokes output of 10.32 W at 1176 nm is achieved under the incident pump power of 39 W and pulse repetition frequency of 160 kHz. The corresponding optical efficiency reaches 26.4%, and even higher efficiency of 27.8% is obtained at lower incident pump of 34.4 W.
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We report an actively Q-switched Nd:YVO4/YVO4 intracavity Raman laser at second-Stokes wavelength of 1313.6 nm, which is capable of operating efficiently under pulse repetition frequency higher than 80 kHz. A folded coupled cavity is adopted to optimize the fundamental and the Stokes resonators individually and make full use of the high pump intensity on the Raman crystal. With relatively high output coupling of 82% at 1313 nm, the average output power of 5.16 W at 1313 nm is achieved under the incident pump power of 36.7 W. The cascaded Raman emission at both the first- and second-Stokes wavelength of 1176 and 1313 nm is investigated to discuss the optimization of the second-Stokes generation.
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BACKGROUND: Chronic exposure to fine ambient particulate matter (PM2.5) induces insulin resistance. CC-chemokine receptor 2 (CCR2) appears to be essential in diet-induced insulin resistance implicating an important role for systemic cellular inflammation in the process. We have previously suggested that CCR2 is important in PM2.5 exposure-mediated inflammation leading to insulin resistance under high fat diet situation. The present study assessed the importance of CCR2 in PM2.5 exposure-induced insulin resistance in the context of normal diet. METHODS AND RESULTS: C57BL/6 and CCR2-/- mice were subjected to exposure to concentrated ambient PM2.5 or filtered air for 6 months. In C57BL/6 mice, concentrated ambient PM2.5 exposure induced whole-body insulin resistance, macrophage infiltration into the adipose tissue, and upregulation of phosphoenolpyruvate carboxykinase (PEPCK) in the liver. While CCR2 deficiency reduced adipose macrophage content in the PM2.5-exposed animals, it did not improve systemic insulin resistance. This lack of improvement in insulin resistance was paralleled by increased hepatic expression of genes in PEPCK and inflammation. CONCLUSION: CCR2 deletion failed to attenuate PM2.5 exposure-induced insulin resistance in mice fed on normal diet. The present study indicates that PM2.5 may dysregulate glucose metabolism directly without exerting proinflammatory effects.
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Contaminantes Atmosféricos/toxicidad , Resistencia a la Insulina , Material Particulado/toxicidad , Receptores CCR2/genética , Tejido Adiposo/efectos de los fármacos , Tejido Adiposo/inmunología , Animales , Dieta , Glucosa/metabolismo , Inflamación , Insulina/metabolismo , Hígado/efectos de los fármacos , Hígado/inmunología , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Ratones Endogámicos C57BL , Ratones Noqueados , Tamaño de la PartículaRESUMEN
BACKGROUND: Atherosclerosis is a progressive disease characterized by the accumulation of lipids and fibrous plaque in the arteries. Its etiology is very complicated and its risk factors primarily include genetic defects, smoking, hyperlipidemia, hypertension, lack of exercise, and infection. Recent studies suggest that fine particulate matter (PM2.5) air pollution may also contribute to the development of atherosclerosis. SCOPE OF REVIEW: The present review integrates current experimental evidence with mechanistic pathways whereby PM2.5 exposure can promote the development of atherosclerosis. MAJOR CONCLUSIONS: PM2.5-mediated enhancement of atherosclerosis is likely due to its pro-oxidant and pro-inflammatory effects, involving multiple organs, different cell types, and various molecular mediators. GENERAL SIGNIFICANCE: Studies about the effects of PM2.5inhalation on atherosclerosis may yield a better understanding of the link between air pollution and major cardiovascular diseases, and provide useful information for policy makers to determine acceptable levels of PM2.5 air quality. This article is part of a Special Issue entitled Air Pollution, edited by Wenjun Ding, Andrew J. Ghio and Weidong Wu.
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Contaminación del Aire/efectos adversos , Aterosclerosis/etiología , Exposición por Inhalación/efectos adversos , Material Particulado/toxicidad , Placa Aterosclerótica/etiología , Especies Reactivas de Oxígeno/agonistas , Aterosclerosis/metabolismo , Aterosclerosis/patología , Células Espumosas/efectos de los fármacos , Células Espumosas/metabolismo , Células Espumosas/patología , Humanos , Hiperlipidemias/fisiopatología , Hipertensión/fisiopatología , Lipoproteínas LDL/agonistas , Lipoproteínas LDL/biosíntesis , Estrés Oxidativo , Tamaño de la Partícula , Placa Aterosclerótica/metabolismo , Placa Aterosclerótica/patología , Especies Reactivas de Oxígeno/metabolismo , Factores de Riesgo , Conducta Sedentaria , Fumar/fisiopatologíaRESUMEN
China has the highest global incidence of hemorrhagic fever with renal syndrome (HFRS), constituting 90% of the cases in the world. Chongqing, located in the Three Gorges Reservoir Region, has been experiencing differences in the occurrence of HFRS from 1997 to 2008. The current study was designed to explore the effects of climate and rodent factors on the transmission of HFRS in Chongqing. Data on monthly HFRS cases, rodent strains, and climatic factors were collected from 1997 to 2008. Spatio-temporal analysis indicated that most HFRS cases were clustered in central Chongqing and that the incidence of HFRS decreased from 1997 to 2008. Poisson regression models showed that temperature (with lagged months of 0 and 5) and rainfall (with 2 lagged months) were key climatic factors contributing to the transmission of HFRS. A zero-inflated negative binomial model revealed that rodent density was also significantly associated with the occurrence of HFRS in the Changshou district. The monthly trend in HFRS incidence was positively associated with rodent density and rainfall and negatively associated with temperature. Possible mechanisms are proposed through which construction of the dam influenced the incidence of HFRS in Chongqing. The findings of this study may contribute to the development of early warning systems for the control and prevention of HFRS in the Three Gorges Reservoir Region.
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Fiebre Hemorrágica con Síndrome Renal/epidemiología , Roedores , Animales , China/epidemiología , Clima , Fiebre Hemorrágica con Síndrome Renal/transmisión , Humanos , Incidencia , Modelos Estadísticos , Densidad de Población , Lluvia , Factores de Riesgo , Roedores/clasificación , Roedores/fisiología , Análisis Espacio-TemporalRESUMEN
BACKGROUND: Exposure to ambient PM2.5 increases cardiovascular mortality and morbidity. To delineate the underlying biological mechanism, we investigated the time dependence of cardiovascular response to chronic exposure to concentrated ambient PM2.5 (CAP). METHODS: Spontaneously hypertensive rats (SHR) were exposed to CAP for 15 weeks, and blood pressure (BP), cardiac function and structure, and inflammations of lung, hypothalamus, and heart were measured at different time points. RESULTS: Chronic exposure to CAP significantly increased BP, and withdrawal from CAP exposure restored BP. Consistent with its BP effect, chronic exposure to CAP significantly decreased cardiac stroke volume and output in SHR, accompanied by increased heart weight and increased cardiac expression of hypertrophic markers ACTA1 and MYH7. Withdrawal from CAP exposure restored cardiac function, weight, and expression of hypertrophic markers, supporting the notion that cardiac dysfunction and hypertrophy is subsequent to hypertension. In agreement with the role of systemic inflammation in mediating the cardiovascular effects of CAP exposure, chronic exposure to CAP markedly increased expression of pro-inflammatory cytokines in lung, heart, and hypothalamus. However, withdrawal from exposure resolves inflammation in the heart and hypothalamus, but not in the lung, suggesting that CAP exposure-induced systemic inflammation may be independent of pulmonary inflammation. CONCLUSION: Chronic exposure to CAP induces reversible cardiac dysfunction and hypertrophy, which is likely to be subsequent to the elevation in BP and induction of systemic inflammation as evidenced by increased mRNA expression of pro-inflammatory cytokines in diverse tissues.