All over the world women are the predominant providers of informal care for family members with chronic medical conditions or disabilities, including the elderly and adults with mental illnesses. It has been suggested...All over the world women are the predominant providers of informal care for family members with chronic medical conditions or disabilities, including the elderly and adults with mental illnesses. It has been suggested that there are several societal and cultural demands on women to adopt the role of a family-caregiver. Stress-coping theories propose that women are more likely to be exposed to caregiving stressors, and are likely to perceive, report and cope with these stressors differently from men. Many studies, which have examined gender differences among family-caregivers of people with mental illnesses, have concluded that women spend more time in providing care and carry out personal-care tasks more often than men. These studies have also found that women experience greater mental and physical strain, greater caregiver-burden, and higher levels of psychological distress while providing care. However, almost an equal number of studies have not found any differences between men and women on these aspects. This has led to the view that though there may be certain differences between male and female caregivers, most of these are small in magnitude and of doubtful clinical significance. Accordingly, caregivergender is thought to explain only a minor proportion of the variance in negative caregiving outcomes. A similar inconsistency characterizes the explanations provided for gender differences in caregiving such as role expectations, differences in stress, coping and social support, and response biases in reporting distress. Apart from the equivocal and inconsistent evidence, there are other problems in the literature on gender differences in caregiving. Most of the evidence has been derived from studies on caregivers of elderly people who either suffer from dementia or other physical conditions. Similar research on other mental illnesses such as schizophrenia or mood disorders is relatively scarce. With changing demographics and social norms men are increasingly assuming roles as caregivers. However, the experience of men while providing care has not been explored adequately. The impact of gender on caregiving outcomes may be mediated by several other variables including patient-related factors, socio-demographic variables, and effects of kinship status, culture and ethnicity, but these have seldom been considered in the research on gender differences. Finally, it is apparent that methodological variations in samples, designs andassessments between studies contribute a great deal to the observed gender differences. This review highlights all these issues and concludes that there is much need for further research in this area if the true nature of gender differences in family-caregiving of mental illnesses is to be discerned.展开更多
Over the span of years, improvements over various synthesis methods of graphene are constantly pursued to provide safer and more effective alternatives. Though the extraction of graphene through Hummers method is one ...Over the span of years, improvements over various synthesis methods of graphene are constantly pursued to provide safer and more effective alternatives. Though the extraction of graphene through Hummers method is one of the oldest techniques yet it is one of the most suitable methods for the formation of bulk graphene. Graphene can be obtained in the form of reduced Graphite oxide, sometimes also referred as Graphene oxide. The effectiveness of this oxidation process can be evaluated by the magnitude of carbon/oxygen ratio of the obtained graphene. Here, graphene oxide (GO) was prepared by oxidizing the purified natural flake graphite (NFG) by a modified Hummers method. The attempts have been made to synthesize GO having few layers by using a modified Hummers method where the amount of NaNO3 has been decreased, and the amount of KMnO4 is increased. The reaction has been performed in a 9:1 (by volume) mixture of H2SO4/H3PO4. This modification is successful in increasing the reaction yield and reducing the toxic gas evolution while using a varied proportion of KMnO4 and H2SO4 as those required by Hummers method. A new component of K2S2O8 has been introduced to the reaction system to maintain the pH value. Reduced graphene oxide (rGO) was thereafter extracted by thermal modification of GO. Here, GO has been used as a precursor for graphene synthesis by thermal reduction processes. The results of FTIR and Raman spectroscopy analysis show that the NFG when oxidized by strong oxidants like KMnO4 and NaNO3, introduced oxygen atoms into the graphite layers and formed bonds like C=O, C-H, COOH and C-O-C with the carbon atoms in the graphite layers. The structure and morphology of both GO and rGO were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy, Raman spectroscopy, Brunauer-Emmett-Teller (BET) surface area analysis and differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).展开更多
In the present investigation the possibility of using exfoliated graphite nanoplatelets (xGnP) as reinforcement in order to enhance the mechanical properties of Cu-based metal matrix composites is explored. Cu-based m...In the present investigation the possibility of using exfoliated graphite nanoplatelets (xGnP) as reinforcement in order to enhance the mechanical properties of Cu-based metal matrix composites is explored. Cu-based metal matrix composites reinforced with different amounts of xGnP were fabricated by powder metallurgy route. The microstructure, sliding wear behaviour and mechanical properties of the Cu-xGnP composites were investigated. xGnP has been synthesized from the graphite intercalation compounds (GIC) through rapid evaporation of the intercalant at an elevated temperature. The thermally exfoliated graphite was later sonicated for a period of 5 h in acetone in order to achieve further exfoliation. The xGnP synthesized was characterized using SEM, HRTEM, X-ray diffraction, Raman spectroscopy and Fourier transform infrared spectroscopy. The Cu and xGnP powder mixtures were consolidated under a load of 565 MPa followed by sintering at 850°C for 2 h in inert atmosphere. Cu-1, 2, 3 and 5 wt% xGnP composites were developed. Results of the wear test show that there is a significant improvement in the wear resistance of the composites up to addition of 2 wt% of xGnP. Hardness, tensile strength and strain at failure of the various Cu-xGnP composites also show improvement upto the addition of 2 wt% xGnP beyond which there is a decrease in these properties. The density of the composites decreases with the addition of higher wt% of xGnP although addition of higher wt% of xGnP leads to higher sinterability and densification of the composites, resulting in higher relative density values. The nature of fracture in the pure Cu as well as the various Cu-xGnP composites was found to be ductile. Nanoplatelets of graphite were found firmly embedded in the Cu matrix in case of Cu-xGnP composites containing low wt% of xGnP.展开更多
For decades,the gut has been thought to play an important role in sepsis pathogenesis.Sepsis is a serious life-threatening,chronic condition of an infection caused by dysregulated host immune response in most of the i...For decades,the gut has been thought to play an important role in sepsis pathogenesis.Sepsis is a serious life-threatening,chronic condition of an infection caused by dysregulated host immune response in most of the intensive care unit patients.Probiotics have dual roles in polymicrobial sepsis i.e.probiotics may induce sepsis in many cases and may prevent its prognosis in many cases.Experimental evidence from both pre-clinical and clinical studies have demonstrated that probiotic therapy ameliorates various inflammatory mediators such as tumor necrosis factor,interleukin-10(IL-10),IL-6,etc.,in septicemia.In addition,probiotic use was also found to reduce the severity of pathological conditions associated with irritable bowel disorder and prevent development of endocarditis in septicemia.On contrary,probiotic therapy in neonatal and athymic adult mice fail to provide any beneficial effects on mortality and sepsis-induced inflammation.Importantly,in few clinical trials probiotic use was found to aggravate sepsis by promoting inflammatory cascade rather than suppressing it.This review discusses various studies regarding the beneficial or harmful effects associated with probiotic therapy in sepsis.展开更多
文摘All over the world women are the predominant providers of informal care for family members with chronic medical conditions or disabilities, including the elderly and adults with mental illnesses. It has been suggested that there are several societal and cultural demands on women to adopt the role of a family-caregiver. Stress-coping theories propose that women are more likely to be exposed to caregiving stressors, and are likely to perceive, report and cope with these stressors differently from men. Many studies, which have examined gender differences among family-caregivers of people with mental illnesses, have concluded that women spend more time in providing care and carry out personal-care tasks more often than men. These studies have also found that women experience greater mental and physical strain, greater caregiver-burden, and higher levels of psychological distress while providing care. However, almost an equal number of studies have not found any differences between men and women on these aspects. This has led to the view that though there may be certain differences between male and female caregivers, most of these are small in magnitude and of doubtful clinical significance. Accordingly, caregivergender is thought to explain only a minor proportion of the variance in negative caregiving outcomes. A similar inconsistency characterizes the explanations provided for gender differences in caregiving such as role expectations, differences in stress, coping and social support, and response biases in reporting distress. Apart from the equivocal and inconsistent evidence, there are other problems in the literature on gender differences in caregiving. Most of the evidence has been derived from studies on caregivers of elderly people who either suffer from dementia or other physical conditions. Similar research on other mental illnesses such as schizophrenia or mood disorders is relatively scarce. With changing demographics and social norms men are increasingly assuming roles as caregivers. However, the experience of men while providing care has not been explored adequately. The impact of gender on caregiving outcomes may be mediated by several other variables including patient-related factors, socio-demographic variables, and effects of kinship status, culture and ethnicity, but these have seldom been considered in the research on gender differences. Finally, it is apparent that methodological variations in samples, designs andassessments between studies contribute a great deal to the observed gender differences. This review highlights all these issues and concludes that there is much need for further research in this area if the true nature of gender differences in family-caregiving of mental illnesses is to be discerned.
文摘Over the span of years, improvements over various synthesis methods of graphene are constantly pursued to provide safer and more effective alternatives. Though the extraction of graphene through Hummers method is one of the oldest techniques yet it is one of the most suitable methods for the formation of bulk graphene. Graphene can be obtained in the form of reduced Graphite oxide, sometimes also referred as Graphene oxide. The effectiveness of this oxidation process can be evaluated by the magnitude of carbon/oxygen ratio of the obtained graphene. Here, graphene oxide (GO) was prepared by oxidizing the purified natural flake graphite (NFG) by a modified Hummers method. The attempts have been made to synthesize GO having few layers by using a modified Hummers method where the amount of NaNO3 has been decreased, and the amount of KMnO4 is increased. The reaction has been performed in a 9:1 (by volume) mixture of H2SO4/H3PO4. This modification is successful in increasing the reaction yield and reducing the toxic gas evolution while using a varied proportion of KMnO4 and H2SO4 as those required by Hummers method. A new component of K2S2O8 has been introduced to the reaction system to maintain the pH value. Reduced graphene oxide (rGO) was thereafter extracted by thermal modification of GO. Here, GO has been used as a precursor for graphene synthesis by thermal reduction processes. The results of FTIR and Raman spectroscopy analysis show that the NFG when oxidized by strong oxidants like KMnO4 and NaNO3, introduced oxygen atoms into the graphite layers and formed bonds like C=O, C-H, COOH and C-O-C with the carbon atoms in the graphite layers. The structure and morphology of both GO and rGO were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy, Raman spectroscopy, Brunauer-Emmett-Teller (BET) surface area analysis and differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).
文摘In the present investigation the possibility of using exfoliated graphite nanoplatelets (xGnP) as reinforcement in order to enhance the mechanical properties of Cu-based metal matrix composites is explored. Cu-based metal matrix composites reinforced with different amounts of xGnP were fabricated by powder metallurgy route. The microstructure, sliding wear behaviour and mechanical properties of the Cu-xGnP composites were investigated. xGnP has been synthesized from the graphite intercalation compounds (GIC) through rapid evaporation of the intercalant at an elevated temperature. The thermally exfoliated graphite was later sonicated for a period of 5 h in acetone in order to achieve further exfoliation. The xGnP synthesized was characterized using SEM, HRTEM, X-ray diffraction, Raman spectroscopy and Fourier transform infrared spectroscopy. The Cu and xGnP powder mixtures were consolidated under a load of 565 MPa followed by sintering at 850°C for 2 h in inert atmosphere. Cu-1, 2, 3 and 5 wt% xGnP composites were developed. Results of the wear test show that there is a significant improvement in the wear resistance of the composites up to addition of 2 wt% of xGnP. Hardness, tensile strength and strain at failure of the various Cu-xGnP composites also show improvement upto the addition of 2 wt% xGnP beyond which there is a decrease in these properties. The density of the composites decreases with the addition of higher wt% of xGnP although addition of higher wt% of xGnP leads to higher sinterability and densification of the composites, resulting in higher relative density values. The nature of fracture in the pure Cu as well as the various Cu-xGnP composites was found to be ductile. Nanoplatelets of graphite were found firmly embedded in the Cu matrix in case of Cu-xGnP composites containing low wt% of xGnP.
文摘For decades,the gut has been thought to play an important role in sepsis pathogenesis.Sepsis is a serious life-threatening,chronic condition of an infection caused by dysregulated host immune response in most of the intensive care unit patients.Probiotics have dual roles in polymicrobial sepsis i.e.probiotics may induce sepsis in many cases and may prevent its prognosis in many cases.Experimental evidence from both pre-clinical and clinical studies have demonstrated that probiotic therapy ameliorates various inflammatory mediators such as tumor necrosis factor,interleukin-10(IL-10),IL-6,etc.,in septicemia.In addition,probiotic use was also found to reduce the severity of pathological conditions associated with irritable bowel disorder and prevent development of endocarditis in septicemia.On contrary,probiotic therapy in neonatal and athymic adult mice fail to provide any beneficial effects on mortality and sepsis-induced inflammation.Importantly,in few clinical trials probiotic use was found to aggravate sepsis by promoting inflammatory cascade rather than suppressing it.This review discusses various studies regarding the beneficial or harmful effects associated with probiotic therapy in sepsis.
