Background: A better understanding of the impact of Targeted Interventions (TI) services on Female Sex Worker (FSW) behaviours can help in informing and strengthening future TI efforts under National AIDS Control Prog...Background: A better understanding of the impact of Targeted Interventions (TI) services on Female Sex Worker (FSW) behaviours can help in informing and strengthening future TI efforts under National AIDS Control Programme (NACP). Methods: National Integrated Biological and Behavioural Survey (IBBS) 2014-15 has been analysed in the paper. Descriptive statistics and logistic regression analysis were used to understand factors affecting condom use. Propensity score matching (PSM) was done to understand the impact of the TI services on condom use at the last act and consistent condom use in the last three months among FSWs. Results: Younger FSWs aged 15 - 25 years were 1.4 times (95% CI: 1.04 - 1.77) more likely to use consistent condoms in the last three months compared to older over 45 years after controlling for other socio-economic and programme variables. The matched samples estimate ATET i.e. the average treatment effect on treated for consistent condom use in the last three months shows that a 6.0% (CI: 4.7 - 7.3) increase in consistent condom use in the last three months in the FSWs who received information on STI/HIV from peer educator and outreach worker. There is also a 6.0% (4.7 - 7.2) increase in condom use in the last act for FSWs who received the referral services at STI clinics, HIV testing, and detox centres. Conclusions: It is evident that the TI programme has a positive impact on behavior change among FSWs which can prove beneficial to curtail the spread of HIV to the partners and onward transmission to the general population.展开更多
Alzheimer’s disease (AD) is caused by synaptic failure and the excessive accumulation of misfolded proteins especially Aβ and tau, and associated with memory loss and cognitive impairment. Treatment of AD mainly con...Alzheimer’s disease (AD) is caused by synaptic failure and the excessive accumulation of misfolded proteins especially Aβ and tau, and associated with memory loss and cognitive impairment. Treatment of AD mainly consists of symptomatic therapy and disease-modifying therapy (DMT). Several monotherapies including small molecules or antibodies have been evaluated through multiple clinical trials, but a very few have been approved by the USFDA to intervene the disease’s pathogenesis. Past research has shown multifactorial nature of AD, therefore, multi-target drugs were proposed to target different pathways at the same time, however, currently no rationally designed multi-target directed ligand (MTDL) has been clinically approved. Different combinations and bispecific antibodies are also under development. Novel approaches like stem cell-based therapies, microRNAs, peptides, ADCs and vaccines cast a new hope for AD treatment, however, a number of questions remained to be answered prior to their safe and effective clinical translation. This review explores the small molecules, MTDL, and antibodies (monospecific and bispecific) for the treatment of AD. Finally, future perspectives (stem cell therapy, PROTAC approaches, microRNAs, ADC, peptides and vaccines) are also discussed with regard to their clinical applications and feasibility.展开更多
Platinum on reaction with halogen forms three halides viz., platinum (II) chloride, platinum (II) bromide and platinum (II) iodide, except platinum (II) fluoride. In this research work, the not existence of PtF<sub...Platinum on reaction with halogen forms three halides viz., platinum (II) chloride, platinum (II) bromide and platinum (II) iodide, except platinum (II) fluoride. In this research work, the not existence of PtF<sub>2</sub> has been studied theoretically. For this thermodynamic, valence bond theory and molecular orbital theory based study have also been performed on this molecule. In order to obtain minimum energy structure we optimized the geometry of this halide by opting AM1 for thermodynamic work and EHT for population analysis. All the calculations were performed on CAChe software. The thermodynamic study supported the presumption of disproportion reaction: 2PtF<sub>2</sub> →Pt + PtF<sub>4</sub>. V.B.T showed sd-hybridization rather than sp-hybridization. This was supported by our data as evaluated theoretically by adopting Landis concept, which showed negligible contribution of 5s-orbital of platinum. Mulliken’s population analysis based studies have pointed that the overlap is very poor due to the dis-similarity of energy of combining orbitals of Pt and F atom. The ΣΦ is very small that is 0.2. This also proved that PtF<sub>2</sub> failed to match the criteria of overlapping and thus MOT too. Using eigenvalues and population analysis MO diagram has also been drawn, which clearly supported non-existence of PtF<sub>2</sub> in nature but its existence in situ and thus also supported the presumption of disproportionation reaction.展开更多
Purpose: Ranitidine hydrochloride (HCl) remains an important medication for treating acid-peptic ailments such as Gastroesophageal reflux disease (GERD). The main objective of this Post Marketing Surveillance (PMS) cl...Purpose: Ranitidine hydrochloride (HCl) remains an important medication for treating acid-peptic ailments such as Gastroesophageal reflux disease (GERD). The main objective of this Post Marketing Surveillance (PMS) clinical study was to test the efficacy and safety of Ranitidine HCl in Indian patients suffering from GERD. Patients and Methods: Data of 2446 patients (1307 males;1121 females) from 21 centers across India were analyzed. Patients received either of the three treatments: Ranitidine HCl 150 mg twice a day (BID) (ARM-A), Ranitidine HCl 300 mg once daily (OD) or BID (ARM-B), and Ranitidine HCl 300 mg OD (ARM-C). Gastroesophageal Reflux Disease Symptom Assessment Scale (GSAS) score and Heartburn Severity score were used to assess the drug’s efficacy. The adverse events reported by patients or investigators were analyzed to assess the safety profile of Ranitidine. Results: Of the 2446 subjects screened, 2428 were enrolled. There was a significant reduction in GSAS scores from baseline to the end of the study visit in all three ARMs. The GSAS scores reduced from 2.02 to 0.23 in ARM-A, 2.01 to 0.24 in ARM-B, and 2.07 to 0.26 in ARM-C patients. In ARM A, 72.82% had 24 hours heartburn-free days, and 66.89% had 7 consecutive heartburn-free days, which was more significant than the other two ARMs. 128 (5.27%) patients reported ADRs due to Ranitidine HCl at different doses. The most frequently reported ADR was constipation (17.18%), followed by oliguria (14.06%), cold (13.28%), and dysuria (12.5%). Of 128 ADRs, 113 (88.28%) were mild, and only 11 (8.59%) ADRs were related to the study drug. No severe ADRs were reported during the study. Conclusion: Ranitidine HCl 150/300 mg tablet was found to be an effective and safe H2-receptor antagonist for treating GERD in Indian Patients.展开更多
Prediction of antagonistic activity of <em>β</em>-carboline and its thirteen derivatives has been made using topological descriptors viz, connectivity index, and kappa shape index of different orders. For...Prediction of antagonistic activity of <em>β</em>-carboline and its thirteen derivatives has been made using topological descriptors viz, connectivity index, and kappa shape index of different orders. For evaluation of values of descriptor, molecular modeling and geometry optimization of all the compounds were carried out with CAChe Pro software by opting semiempirical PM3 method using MOPAC 2002. For prediction of activity multiple linear regression analysis (MLR) was performed. MLR analysis has been made by Project Leader Software associated with CAChe by using the above descriptors as independent variables and biological activity as dependent variables. We were performed leave-one-out methods and the result reflected a direct relationship between biological activity and connectivity index of zero order, while indirect relationship with connectivity index of second order and thus connectivity index is a reliable descriptor to predict the biological activity of <em>β</em>-carboline and its various derivatives.展开更多
Gluteal hernias are extremely uncommon and occur as a result of deficiency or defect in the gluteal musculature. Our case reports one such incidence in a one year old girl with review of available literature. The clin...Gluteal hernias are extremely uncommon and occur as a result of deficiency or defect in the gluteal musculature. Our case reports one such incidence in a one year old girl with review of available literature. The clinical presentation and imaging findings are discussed comprehensively. We thus lay emphasis on the importance of real-time ultrasonography as the method of choice to identify hernia contents, peristalsis and obstruction if any.展开更多
<i><span style="font-family:Verdana;">Nepeta cataria</span></i><span style="font-family:Verdana;"> L.</span><span style="font-family:Verdana;">, ...<i><span style="font-family:Verdana;">Nepeta cataria</span></i><span style="font-family:Verdana;"> L.</span><span style="font-family:Verdana;">, commonly known as catmint or catnip, belongs to the family </span><span style="font-family:Verdana;">“</span><span style="font-family:Verdana;">Lamiaceae</span><span style="font-family:Verdana;">”</span><span style="font-family:""><span style="font-family:Verdana;"> and is indigenous to Europe and Asia. The essential oil of this species is known for the richness and diversity of nepetalactones (NPL) which are used as mosquito/insect repellents in perfumery and cosmetic industries. Reports on Indian catmint germplasm are very meager and warrants exploration of its commercial potential as a natural, non-toxic source of insect repellents. With this objective, commercial open-pollinated seeds of catmint collected from its native, temperate habitat in Himalayas were introduced in the tropical plains. Subsequent to adaptation to a new zone we were able to isolate nineteen individual plants based on plant growth. Hydrodistillation of the fresh herb yielded essential oil in the range of 0.01% to 0.2%. Gas Chromatography (GC) and GC-Mass Spectrometry (GC-MS) analyses of the oil revealed the dominance of monoterpene hydrocarbon, namely, </span><b><span style="font-family:Verdana;">4aα,7α,7aα NPL</span></b><span style="font-family:Verdana;"> (1) isomer (84%). The other two isomers of nepetalactone, </span><b><span style="font-family:Verdana;">4aα,7α,7aβ NPL</span></b><span style="font-family:Verdana;"> (2) and </span><b><span style="font-family:Verdana;">4aα,7β,7aα NPL</span></b><span style="font-family:Verdana;"> (3) were also present, although in very </span></span><span style="font-family:Verdana;">less</span><span style="font-family:"color:red;"> </span><span style="font-family:""><span style="font-family:Verdana;">amounts (1.0% and 1.6%, respectively). Sesquiterpenes identified were α-humulene (traces), (</span><i><span style="font-family:Verdana;">E</span></i><s展开更多
The refinement potential of AI-3.5FeNb-I.5C master alloy on pure aluminium and AI-9.8Si-3.4Cu alloy has been investigated. Different amounts of AI-3.5FeNb-I.5C master alloy were added to estimate the optimal addition ...The refinement potential of AI-3.5FeNb-I.5C master alloy on pure aluminium and AI-9.8Si-3.4Cu alloy has been investigated. Different amounts of AI-3.5FeNb-I.5C master alloy were added to estimate the optimal addition level. It was found that the addition of AI-3.5FeNb-I.5C grain refiner can promote significantly the refinement of grains in the pure aluminium, particularly at 0.1wt.%, with the mean primary aluminium a-grain size reducing to 187＋3 IJm from about 1-3 mm. Similarly, the microstructural study of the AI-9.8Si-3.4Cu alloy die casting at different weight percentages （viz. 0.0wt.%, 0.1wt.% and 1.0wt.%） of AI-3.5FeNb-I.5C master alloy shows that the AI-3.5FeNb-I.5C master alloy as a grain refiner is also acceptable for AI-Si cast alloys when the silicon content is more than 4wt.%. As a result of inoculation with AI-3.5FeNb-1.5C master alloy, the average grain size of a-AI is reduced to 22＋3 #m from about 71＋3 IJm and grain refining efficiency is not characterized by any visible poisoning effect, which is the major limitation in the grain refinement of AI-Si cast alloys by applying AI-Ti-B ternary master alloys. Mechanical properties such as ultimate tensile strength and yield strength are significantly improved by 9.6% and 9.7%, respectively.展开更多
The BEAMnrc code was used for the simulation of the Theratron Equinox-80 telecobalt machine. The phase space of radiation beam was generated at treatment distance of 80 cm for various field sizes. The phase spaces in ...The BEAMnrc code was used for the simulation of the Theratron Equinox-80 telecobalt machine. The phase space of radiation beam was generated at treatment distance of 80 cm for various field sizes. The phase spaces in air were analyzed by BEAMdp data processing program. The electron energy fluence with respect to photon energy was 0.09% and 0.34% for field size of 05 × 05 and 35 × 35 cm<sup>2</sup> respectively and it was maximum at the central axis which gradually decreases beyond this. The profiles for photon fluence were in symmetry for all the fields. The full width at half maximum of profiles in photon energy fluence shows good agreement with the field size. The photon energy fluence was flat till the field size of 27 cm<sup>2</sup>, after which it decreases gradually till the edge in larger field sizes. The air-kerma output factor from the simulation was in good agreement with measured value. We analyzed the dose data scored in the voxels in a large water phantom by simulation using dosxyznrc code. The percentage depth dose for all field sizes was in good agreement with the BJR supplement 25 and the data supplied by the manufacturer of machine. Significant deviation of about 20% in isodose line near the edge of the profile was observed for 35 × 35 cm<sup>2</sup> field size. The penumbra widths of all field sizes were comparable except for 35 × 35 cm<sup>2</sup>, which has a penumbra width of 4.1 cm at 10 cm depth. The significant under dose near the edge as compared to central axis for larger field sizes may be the indication for its careful use in treatment.展开更多
The purpose of carrying out present work is to design, build and test a rhombic drive Stirling engine with a β-type configuration consisting of two dynamic pistons (displacer and power) reciprocates in the in-line co...The purpose of carrying out present work is to design, build and test a rhombic drive Stirling engine with a β-type configuration consisting of two dynamic pistons (displacer and power) reciprocates in the in-line concentric cylinder arrangement. The displacement rod is assembled concentrically inside the power piston rod. The rhombic drive mechanism is proposed in such a way that, by using a pair of gear wheels the sliding motion of both piston rods is controlled and thus, an engine is balanced. The developed prototype has a swept volume of 75 cm<sup>3</sup> with the displacer piston and power piston cylinder hot ends heated by liquefied petroleum gas (LPG) burner and cooled water, respectively. It uses air as the working gas at atmospheric pressure for initial charging of the engine. Several designs were studied before settling on a β-type configuration. The LPG gas burner was considered as a potential heat source. The various elements of an engine (heater, cooler, re-generator, flywheel and piping systems) were designed, constructed and analyzed. The testing results revealed that the engine at initial atmospheric air filling started working in only about 120 seconds at an LPG heater temperature of 400℃ (824<sup>°</sup>F) with 280 rpm. At a heater temperature of 550℃ (1022<sup>°</sup>F), the engine speed was 630 rpm. At the engine speed of 245 rpm, the maximum torque was 0.215 Nm, while the maximum power was 8 Watts at 355 rpm. Engine speed increased with the increase of flame temperature. Several tests were performed on the engine to improve its running efficiency and critical problem areas were isolated and addressed. Moreover, results revealed that Stirling engines working with relatively low-temperature air are potentially attractive engines of the future, especially LPG powered low temperature differential Stirling engines. The Stirling engine was capable of generating between 50 to 100 Watts of electricity.展开更多
文摘Background: A better understanding of the impact of Targeted Interventions (TI) services on Female Sex Worker (FSW) behaviours can help in informing and strengthening future TI efforts under National AIDS Control Programme (NACP). Methods: National Integrated Biological and Behavioural Survey (IBBS) 2014-15 has been analysed in the paper. Descriptive statistics and logistic regression analysis were used to understand factors affecting condom use. Propensity score matching (PSM) was done to understand the impact of the TI services on condom use at the last act and consistent condom use in the last three months among FSWs. Results: Younger FSWs aged 15 - 25 years were 1.4 times (95% CI: 1.04 - 1.77) more likely to use consistent condoms in the last three months compared to older over 45 years after controlling for other socio-economic and programme variables. The matched samples estimate ATET i.e. the average treatment effect on treated for consistent condom use in the last three months shows that a 6.0% (CI: 4.7 - 7.3) increase in consistent condom use in the last three months in the FSWs who received information on STI/HIV from peer educator and outreach worker. There is also a 6.0% (4.7 - 7.2) increase in condom use in the last act for FSWs who received the referral services at STI clinics, HIV testing, and detox centres. Conclusions: It is evident that the TI programme has a positive impact on behavior change among FSWs which can prove beneficial to curtail the spread of HIV to the partners and onward transmission to the general population.
文摘Alzheimer’s disease (AD) is caused by synaptic failure and the excessive accumulation of misfolded proteins especially Aβ and tau, and associated with memory loss and cognitive impairment. Treatment of AD mainly consists of symptomatic therapy and disease-modifying therapy (DMT). Several monotherapies including small molecules or antibodies have been evaluated through multiple clinical trials, but a very few have been approved by the USFDA to intervene the disease’s pathogenesis. Past research has shown multifactorial nature of AD, therefore, multi-target drugs were proposed to target different pathways at the same time, however, currently no rationally designed multi-target directed ligand (MTDL) has been clinically approved. Different combinations and bispecific antibodies are also under development. Novel approaches like stem cell-based therapies, microRNAs, peptides, ADCs and vaccines cast a new hope for AD treatment, however, a number of questions remained to be answered prior to their safe and effective clinical translation. This review explores the small molecules, MTDL, and antibodies (monospecific and bispecific) for the treatment of AD. Finally, future perspectives (stem cell therapy, PROTAC approaches, microRNAs, ADC, peptides and vaccines) are also discussed with regard to their clinical applications and feasibility.
文摘Platinum on reaction with halogen forms three halides viz., platinum (II) chloride, platinum (II) bromide and platinum (II) iodide, except platinum (II) fluoride. In this research work, the not existence of PtF<sub>2</sub> has been studied theoretically. For this thermodynamic, valence bond theory and molecular orbital theory based study have also been performed on this molecule. In order to obtain minimum energy structure we optimized the geometry of this halide by opting AM1 for thermodynamic work and EHT for population analysis. All the calculations were performed on CAChe software. The thermodynamic study supported the presumption of disproportion reaction: 2PtF<sub>2</sub> →Pt + PtF<sub>4</sub>. V.B.T showed sd-hybridization rather than sp-hybridization. This was supported by our data as evaluated theoretically by adopting Landis concept, which showed negligible contribution of 5s-orbital of platinum. Mulliken’s population analysis based studies have pointed that the overlap is very poor due to the dis-similarity of energy of combining orbitals of Pt and F atom. The ΣΦ is very small that is 0.2. This also proved that PtF<sub>2</sub> failed to match the criteria of overlapping and thus MOT too. Using eigenvalues and population analysis MO diagram has also been drawn, which clearly supported non-existence of PtF<sub>2</sub> in nature but its existence in situ and thus also supported the presumption of disproportionation reaction.
文摘Purpose: Ranitidine hydrochloride (HCl) remains an important medication for treating acid-peptic ailments such as Gastroesophageal reflux disease (GERD). The main objective of this Post Marketing Surveillance (PMS) clinical study was to test the efficacy and safety of Ranitidine HCl in Indian patients suffering from GERD. Patients and Methods: Data of 2446 patients (1307 males;1121 females) from 21 centers across India were analyzed. Patients received either of the three treatments: Ranitidine HCl 150 mg twice a day (BID) (ARM-A), Ranitidine HCl 300 mg once daily (OD) or BID (ARM-B), and Ranitidine HCl 300 mg OD (ARM-C). Gastroesophageal Reflux Disease Symptom Assessment Scale (GSAS) score and Heartburn Severity score were used to assess the drug’s efficacy. The adverse events reported by patients or investigators were analyzed to assess the safety profile of Ranitidine. Results: Of the 2446 subjects screened, 2428 were enrolled. There was a significant reduction in GSAS scores from baseline to the end of the study visit in all three ARMs. The GSAS scores reduced from 2.02 to 0.23 in ARM-A, 2.01 to 0.24 in ARM-B, and 2.07 to 0.26 in ARM-C patients. In ARM A, 72.82% had 24 hours heartburn-free days, and 66.89% had 7 consecutive heartburn-free days, which was more significant than the other two ARMs. 128 (5.27%) patients reported ADRs due to Ranitidine HCl at different doses. The most frequently reported ADR was constipation (17.18%), followed by oliguria (14.06%), cold (13.28%), and dysuria (12.5%). Of 128 ADRs, 113 (88.28%) were mild, and only 11 (8.59%) ADRs were related to the study drug. No severe ADRs were reported during the study. Conclusion: Ranitidine HCl 150/300 mg tablet was found to be an effective and safe H2-receptor antagonist for treating GERD in Indian Patients.
文摘Prediction of antagonistic activity of <em>β</em>-carboline and its thirteen derivatives has been made using topological descriptors viz, connectivity index, and kappa shape index of different orders. For evaluation of values of descriptor, molecular modeling and geometry optimization of all the compounds were carried out with CAChe Pro software by opting semiempirical PM3 method using MOPAC 2002. For prediction of activity multiple linear regression analysis (MLR) was performed. MLR analysis has been made by Project Leader Software associated with CAChe by using the above descriptors as independent variables and biological activity as dependent variables. We were performed leave-one-out methods and the result reflected a direct relationship between biological activity and connectivity index of zero order, while indirect relationship with connectivity index of second order and thus connectivity index is a reliable descriptor to predict the biological activity of <em>β</em>-carboline and its various derivatives.
文摘Gluteal hernias are extremely uncommon and occur as a result of deficiency or defect in the gluteal musculature. Our case reports one such incidence in a one year old girl with review of available literature. The clinical presentation and imaging findings are discussed comprehensively. We thus lay emphasis on the importance of real-time ultrasonography as the method of choice to identify hernia contents, peristalsis and obstruction if any.
文摘<i><span style="font-family:Verdana;">Nepeta cataria</span></i><span style="font-family:Verdana;"> L.</span><span style="font-family:Verdana;">, commonly known as catmint or catnip, belongs to the family </span><span style="font-family:Verdana;">“</span><span style="font-family:Verdana;">Lamiaceae</span><span style="font-family:Verdana;">”</span><span style="font-family:""><span style="font-family:Verdana;"> and is indigenous to Europe and Asia. The essential oil of this species is known for the richness and diversity of nepetalactones (NPL) which are used as mosquito/insect repellents in perfumery and cosmetic industries. Reports on Indian catmint germplasm are very meager and warrants exploration of its commercial potential as a natural, non-toxic source of insect repellents. With this objective, commercial open-pollinated seeds of catmint collected from its native, temperate habitat in Himalayas were introduced in the tropical plains. Subsequent to adaptation to a new zone we were able to isolate nineteen individual plants based on plant growth. Hydrodistillation of the fresh herb yielded essential oil in the range of 0.01% to 0.2%. Gas Chromatography (GC) and GC-Mass Spectrometry (GC-MS) analyses of the oil revealed the dominance of monoterpene hydrocarbon, namely, </span><b><span style="font-family:Verdana;">4aα,7α,7aα NPL</span></b><span style="font-family:Verdana;"> (1) isomer (84%). The other two isomers of nepetalactone, </span><b><span style="font-family:Verdana;">4aα,7α,7aβ NPL</span></b><span style="font-family:Verdana;"> (2) and </span><b><span style="font-family:Verdana;">4aα,7β,7aα NPL</span></b><span style="font-family:Verdana;"> (3) were also present, although in very </span></span><span style="font-family:Verdana;">less</span><span style="font-family:"color:red;"> </span><span style="font-family:""><span style="font-family:Verdana;">amounts (1.0% and 1.6%, respectively). Sesquiterpenes identified were α-humulene (traces), (</span><i><span style="font-family:Verdana;">E</span></i><s
基金financially supported by the National Institute of Technology(NIT),Manipur-India to carry out the industrial experimental research work
文摘The refinement potential of AI-3.5FeNb-I.5C master alloy on pure aluminium and AI-9.8Si-3.4Cu alloy has been investigated. Different amounts of AI-3.5FeNb-I.5C master alloy were added to estimate the optimal addition level. It was found that the addition of AI-3.5FeNb-I.5C grain refiner can promote significantly the refinement of grains in the pure aluminium, particularly at 0.1wt.%, with the mean primary aluminium a-grain size reducing to 187＋3 IJm from about 1-3 mm. Similarly, the microstructural study of the AI-9.8Si-3.4Cu alloy die casting at different weight percentages （viz. 0.0wt.%, 0.1wt.% and 1.0wt.%） of AI-3.5FeNb-I.5C master alloy shows that the AI-3.5FeNb-I.5C master alloy as a grain refiner is also acceptable for AI-Si cast alloys when the silicon content is more than 4wt.%. As a result of inoculation with AI-3.5FeNb-1.5C master alloy, the average grain size of a-AI is reduced to 22＋3 #m from about 71＋3 IJm and grain refining efficiency is not characterized by any visible poisoning effect, which is the major limitation in the grain refinement of AI-Si cast alloys by applying AI-Ti-B ternary master alloys. Mechanical properties such as ultimate tensile strength and yield strength are significantly improved by 9.6% and 9.7%, respectively.
文摘The BEAMnrc code was used for the simulation of the Theratron Equinox-80 telecobalt machine. The phase space of radiation beam was generated at treatment distance of 80 cm for various field sizes. The phase spaces in air were analyzed by BEAMdp data processing program. The electron energy fluence with respect to photon energy was 0.09% and 0.34% for field size of 05 × 05 and 35 × 35 cm<sup>2</sup> respectively and it was maximum at the central axis which gradually decreases beyond this. The profiles for photon fluence were in symmetry for all the fields. The full width at half maximum of profiles in photon energy fluence shows good agreement with the field size. The photon energy fluence was flat till the field size of 27 cm<sup>2</sup>, after which it decreases gradually till the edge in larger field sizes. The air-kerma output factor from the simulation was in good agreement with measured value. We analyzed the dose data scored in the voxels in a large water phantom by simulation using dosxyznrc code. The percentage depth dose for all field sizes was in good agreement with the BJR supplement 25 and the data supplied by the manufacturer of machine. Significant deviation of about 20% in isodose line near the edge of the profile was observed for 35 × 35 cm<sup>2</sup> field size. The penumbra widths of all field sizes were comparable except for 35 × 35 cm<sup>2</sup>, which has a penumbra width of 4.1 cm at 10 cm depth. The significant under dose near the edge as compared to central axis for larger field sizes may be the indication for its careful use in treatment.
文摘The purpose of carrying out present work is to design, build and test a rhombic drive Stirling engine with a β-type configuration consisting of two dynamic pistons (displacer and power) reciprocates in the in-line concentric cylinder arrangement. The displacement rod is assembled concentrically inside the power piston rod. The rhombic drive mechanism is proposed in such a way that, by using a pair of gear wheels the sliding motion of both piston rods is controlled and thus, an engine is balanced. The developed prototype has a swept volume of 75 cm<sup>3</sup> with the displacer piston and power piston cylinder hot ends heated by liquefied petroleum gas (LPG) burner and cooled water, respectively. It uses air as the working gas at atmospheric pressure for initial charging of the engine. Several designs were studied before settling on a β-type configuration. The LPG gas burner was considered as a potential heat source. The various elements of an engine (heater, cooler, re-generator, flywheel and piping systems) were designed, constructed and analyzed. The testing results revealed that the engine at initial atmospheric air filling started working in only about 120 seconds at an LPG heater temperature of 400℃ (824<sup>°</sup>F) with 280 rpm. At a heater temperature of 550℃ (1022<sup>°</sup>F), the engine speed was 630 rpm. At the engine speed of 245 rpm, the maximum torque was 0.215 Nm, while the maximum power was 8 Watts at 355 rpm. Engine speed increased with the increase of flame temperature. Several tests were performed on the engine to improve its running efficiency and critical problem areas were isolated and addressed. Moreover, results revealed that Stirling engines working with relatively low-temperature air are potentially attractive engines of the future, especially LPG powered low temperature differential Stirling engines. The Stirling engine was capable of generating between 50 to 100 Watts of electricity.
