Background: The segmental multi-frequency bioelectrical impedance analysis (SMF-BIA) is a useful method for evaluating physical health and nutritional status in various clinical settings. But less is known about its r...Background: The segmental multi-frequency bioelectrical impedance analysis (SMF-BIA) is a useful method for evaluating physical health and nutritional status in various clinical settings. But less is known about its role in the preoperative assessment of breast cancer patients. Herein, we try to monitor the changes in body composition of preoperative patients by SMF-BIA and figure out its association with clinical features. Methods: The changes in body composition were monitored by SMF-BIA in 563 female patients with breast cancer. Monitor body moisture and collect relevant data on the day before surgery as a prospective study. Retrospective analysis will be conducted based on preoperative data and pathological results after lymph node resection, Spearman’s correlation coefficients were calculated to investigate the correlation among parameters. Results: We found that the body water, extracellular water ratio, and bioelectrical impedance of the affected upper limbs of patients with different tumor stages or different numbers of lymph node metastases were significantly different from those of their healthy upper limbs (P P P P P Conclusion: SMF-BIA can help monitor the changes in body composition of breast cancer patients and provide detailed information for making a personalized treatment plan and individual nursing schedule. However, the value of SMF-BIA in preoperative assessment still needs to be validated in large prospective clinical trials.展开更多
Objective: To investigate the effect of surgical nursing on grade III Hand-Foot Syndrome (HFS) induced by Doxorubicin hydrochloride liposome chemotherapy after breast cancer surgery. Method: From January 2019 to Decem...Objective: To investigate the effect of surgical nursing on grade III Hand-Foot Syndrome (HFS) induced by Doxorubicin hydrochloride liposome chemotherapy after breast cancer surgery. Method: From January 2019 to December 2019, 10 patients with HFS grade III caused by Doxorubicin hydrochloride liposome chemotherapy after breast cancer surgery in the Breast Department of Cancer Prevention and Treatment Center of Sun Yat-sen University were selected, and surgical nursing methods were used to intervene and observe the therapeutic effects of the patients. Results: One patient was cured within 7 days, the cure rate was 10% in 7 days, 8 patients were cured within 10 days, the cure rate was 80% in 10 days, 10 patients were cured within 15 days, the cure rate was 100% in 15 days. Conclusion: The surgical nursing method is effective for patients with grade III HFS caused by Doxorubicin hydrochloride liposome chemotherapy after breast cancer surgery, shortening the treatment time of HFS, and is worthy of clinical promotion.展开更多
BACKGROUND: Secondary lymphedema is one of the common complications after malignant tumor surgery. It is a chronic and complex disease. Once lymphedema occurs, there will be discomfort such as limb swelling, pain, num...BACKGROUND: Secondary lymphedema is one of the common complications after malignant tumor surgery. It is a chronic and complex disease. Once lymphedema occurs, there will be discomfort such as limb swelling, pain, numbness and tension, which will eventually lead to changes in the appearance of the affected limb and will seriously affect the quality of life and require lifelong treatment and psychosocial support. This study investigated the current situation of stigma and alexithymia in patients with lymphedema, and discussed the impact of alexithymia on stigma in patients with lymphedema. AIMS: To understand the current situation of stigma and alexithymia in patients with lymphedema, and to analyze the influence of alexithymia on stigma. METHODS: 195 patients with lymphedema in a hospital were selected by convenient sampling. General information questionnaire, Toronto Alexithymia Scale and social impact scale were used to investigate respectively, to study the general situation, stigma and alexithymia of the respondents. RESULTS: The results showed that the total score of stigma in 195 patients with lymphedema was (60.36 ± 11.08), and the total score of alexithymia was (56.53 ± 8.43). Multiple linear regression analysis showed that alexithymia and family relationship were the influencing factors of stigma in patients with lymphedema. CONCLUSIONS: The patients with lymphedema have obvious stigma, and alexithymia and family relationship are the influencing factors.展开更多
We show that an intrinsically nonlinear oscillator can always be transformed into a linear or harmonic oscillator by addition of a constant force, which shifts the equilibrium position of the oscillator.
Objective: To explore the pre-treatment and efficacy analysis of comprehensive anti-inflammatory treatment for lymphedema in patients with irritating contact dermatitis. Method: Convenience sampling method was used to...Objective: To explore the pre-treatment and efficacy analysis of comprehensive anti-inflammatory treatment for lymphedema in patients with irritating contact dermatitis. Method: Convenience sampling method was used to observe the skin of 160 patients with upper limb lymphedema admitted to the lymphedema outpatient department of our hospital. They were divided into an observation group (80 cases) and a control group (80 cases), and both groups received a course of comprehensive anti-inflammatory treatment (20 treatments). The control group received routine skin care;On the basis of the control group, the observation group received pre-treatment of the affected limb skin: Laofuzi herbal ointment was applied externally to the prone areas of irritating contact dermatitis (such as the upper arm, inner forearm, and cubital fossa). Result: The incidence of irritating contact dermatitis in the observation group was significantly lower than that in the control group (P 0.05). Patients in the observation group felt significantly better in terms of comfort, skin moisture, and itching relief after being wrapped with low elasticity bandages than those in the control group (P Conclusion: Preventive treatment can effectively reduce the incidence of irritating contact dermatitis, prolong the time of stress treatment, thereby increasing efficacy and improving patient compliance.展开更多
Objective: The purpose of the study was to explore the application effects of the cloud platform-based comprehensive online management for breast cancer patients using dual-targeted therapy with macromolecular monoclo...Objective: The purpose of the study was to explore the application effects of the cloud platform-based comprehensive online management for breast cancer patients using dual-targeted therapy with macromolecular monoclonal antibodies. Methods: 120 breast cancer patients treated by dual-targeted therapy with macromolecular monoclonal antibodies were managed by a cloud platform from March to November 2019. Comprehensive online management included consultation about drugs and side effects and frequently asked questions in the dual-targeted therapy with macromolecular monoclonal antibodies. Results: In the consultation about drugs and side effects, there were five patients with fever, neutrophil, cough, and fatigue;24 with diarrhea;25 with nausea;11 with oral mucosal inflammation;10 with rashes and dry skin;8 with insomnia;and 1 with palpitation. Moreover, 110 patients with anxiety about the missed or delayed treatment were properly handled. Conclusion: The comprehensive online management of dual-targeted therapy with macromolecular monoclonal antibodies based on the cloud platform is helpful to satisfy the at-home breast cancer patients’ needs, ensure the continuity of dual-targeted therapy with macromolecular monoclonal antibodies for breast cancer patients, prevent misinformation, alleviate patients’ negative psychological emotions, and reduce patients’ economic losses. The online cloud platform integrated management model is crucial for managing patients with breast cancer treated by dual-targeted therapy.展开更多
This study aimed to develop original laboratory culture and sediment toxicity testing protocols for the freshwater gastropod Bellamya aeruginosa (Reeve), a new potential species for sediment toxicity testing. B. aer...This study aimed to develop original laboratory culture and sediment toxicity testing protocols for the freshwater gastropod Bellamya aeruginosa (Reeve), a new potential species for sediment toxicity testing. B. aeruginosa was successfully cultured with an effective culture system under proposed laboratory conditions. Optimal ad libitum feeding levels for larvae, juveniles, and adults were 2.0, 6.0, and 16.0 mg fish food/(snall.day), respectively. Mean survival rates of juveniles were higher than 90%, The snails could be sexed at 9 weeks of age, and their generation time is approximately 4 months. Reproduction continued all year around; the mean fecundity was 0.55 newborn/(female.day). The utility of this species for bioassays was evaluated in both 10-day and 28-day case studies with artificial sediments. The 10-day LC50 of Cu for larvae was 480 μg/g dry weight (dw), and the lowest observed effects concentration of Cu for survival and growth of larvae was 195 μg/g dw. Survival and growth are reliable indicators of acute toxicity. Larvae accumulated more Cu than adults. B. aeruginosa exhibited a higher sensitivity to Cu exposure than standard test species (Hyalella azteca and Chironomus tentans). The 28-day test of sediment toxicity with adults showed that fecundity was a robust endpoint indicator of reproductive toxicity, and the biochemical endpoints of superoxide dismutase, catalase, and glutathione could be used as sensitive biomarkers for Cu-induced oxidative damage. B. aeruginosa can be therefore recommended as a candidate for the standardization of the freshwater sediment toxicity test protocol.展开更多
The ventral tegmental area and the locus coeruleus are associated with psychological and physical dependence of opioid addiction. To date, very little is known about brain-derived neurotrophic factor (BDNF) and Bcl-...The ventral tegmental area and the locus coeruleus are associated with psychological and physical dependence of opioid addiction. To date, very little is known about brain-derived neurotrophic factor (BDNF) and Bcl-2 gene and protein changes following morphine addiction. The present study utilized immunohistochemistry and in situ hybridization techniques, which revealed that there were increased BDNF levels, but decreased Bcl-2 levels in the prefrontal cortex, locus coeruleus, hippocampus, and the ventral tegmental area during morphine-dependence formation and abstinence. However, the levels of BDNF remained unchanged, and Bcl-2 expression was increased in the nucleus accumbens. These results showed that BDNF and Bcl-2 are involved in the development of morphine dependence, and precipitation of abstinence syndrome.展开更多
BACKGROUND: The four measures used to assess the stability of the Wisconsin card sorting test (WCST), that is, the number of preservative errors, percentage of preservative errors, number of categories completed, a...BACKGROUND: The four measures used to assess the stability of the Wisconsin card sorting test (WCST), that is, the number of preservative errors, percentage of preservative errors, number of categories completed, and the number of trials to complete the first category, reflect the function of the frontal lobe. OBJECTIVE: This study was designed to investigate the effects of asthma on the stability of WCST measurements through the use of a twin study, and to analyze whether egg-type difference exists. DESIGN: A cohort study. SETTING: Mental Health Center, the First Affiliated Hospital of Chongqing Medical University. PARTICIPANTS: Fifty-nine pairs of twins, aged 6-16 years, were primarily selected from schools between August 2005 and February 2007 and the WCST and Zygosity identification test was applied. Twins with achromatopsia, severe upper limb diseases, somatic diseases, or mental disorders were excluded. According to disease history of asthmatic attack, children were assigned into asthma (n = 16) and non-asthma (n = 43) groups. METHODS: Four WCST measurements were determined in the 59 pairs of twins, and egg-type differences were identified in conjunction. RESULTS: All 59 pairs of twins were included in the final analysis. Among the pairs of twins, 28 (48.5 %) were monozygotic twins, and 31 (52%) were dizygotic twins. Among the monozygotic and dizygotic twins, the number of preservative errors and percentage of preservative errors were significantly higher in the asthma group than in the non-asthma group (P 〈 0.05). However, there was no significant difference of each corresponding measure between the monozygotic and dizygotic twins (P 〉 0.05). CONCLUSION: Asthma may affect the stability of WCST measures, but egg-type differences do not exist.展开更多
The purpose of this research is to investigate the sinuosity of major rivers in the United States and the world, and to compare them to that predicted by the existing theories. It is shown that the average sinuosity o...The purpose of this research is to investigate the sinuosity of major rivers in the United States and the world, and to compare them to that predicted by the existing theories. It is shown that the average sinuosity of meandering rivers deviates considerably from what has been reported previously as π. Calculations of the mean value of actual sinuosities of major rivers in the United States and in the World show that this average is very close to 2. Exact models as well as a Monte Carlo simulation for meandering rivers that is based on Gaussian probability distribution function are also presented, and the possibility of composite meandering is discussed.展开更多
Despite several attempts that have been made to explain the twin paradox, which are based on asymmetry and acceleration, it is shown that none of these explanations can resolve the paradox in the general case. Three s...Despite several attempts that have been made to explain the twin paradox, which are based on asymmetry and acceleration, it is shown that none of these explanations can resolve the paradox in the general case. Three specific examples of the twin paradox are provided in which the system is completely symmetric;consequently the existing explanations are not able to resolve the paradox.展开更多
CRISPR‒Cas7-11 is a Type Ⅲ-E CRISPR-associated nuclease that functions as a potent RNA editing tool.Tetratrico-peptide repeat fused with Cas/HEF1-associated signal transducer(TPR-CHAT)acts as a regulatory protein tha...CRISPR‒Cas7-11 is a Type Ⅲ-E CRISPR-associated nuclease that functions as a potent RNA editing tool.Tetratrico-peptide repeat fused with Cas/HEF1-associated signal transducer(TPR-CHAT)acts as a regulatory protein that interacts with CRISPR RNA(crRNA)-bound Cas7-11 to form a CRISPR-guided caspase complex(Craspase).However,the precise modulation of Cas7-11’s nuclease activity by TPR-CHAT to enhance its utility requires further study.Here,we report cryo-electron microscopy(cryo-EM)structures of Desulfonema ishimotonii(Di)Cas7-11-crRNA,complexed with or without the full length or the N-terminus of TPR-CHAT.These structures unveil the molecular features of the Craspase complex.Structural analysis,combined with in vitro nuclease assay and electrophoretic mobility shift assay,reveals that DiTPR-CHAT negatively regulates the activity of DiCas7-11 by preventing target RNA from binding through the N-terminal 65 amino acids of DiTPR-CHAT(DiTPR-CHAT_(NTD)).Our work demonstrates that DiTPRCHAT_(NTD) can function as a small unit of DiCas7-11 regulator,potentially enabling safe applications to prevent overcutting and offtarget effects of the CRISPR‒Cas7-11 system.展开更多
Recently,photodynamic therapy(PDT)has been extensively applied in clinical and coadjuvant treatment of various kinds of tumors.However,the photosensitizer(PS)of PDT still lack of high production of singlet oxygen(^(1)...Recently,photodynamic therapy(PDT)has been extensively applied in clinical and coadjuvant treatment of various kinds of tumors.However,the photosensitizer(PS)of PDT still lack of high production of singlet oxygen(^(1)O_(2)),low cytotoxicity and high biocompatibility.Herein,we propose a facile method for establishing a new core-shell structured Sn nanocluster@carbon dots(CDs)PS.Firstly,Sn^(4+)@S-CDs complex is synthesized using the sulfur-doped CDs(S-CDs)and SnCl4 as raw materials,and subsequently the new PS(Sn nanocluster@CDs)is obtained after vaporization of Sn4+@S-CDs solution.Remarkably,the obtained Sn nanocluster@CDs show an enhanced fluorescence as well as a higher ^(1)O_(2) quantum yield(QY)than S-CDs.The high ^(1)O_(2) QY(58.3%)irradiated by the LED light(400-700 nm,40 mW/cm^(2)),induce the reduction of 4 T1 cancer cells viability by 25%.More intriguingly,no visible damage happens to healthy cells,with little impact on liver tissue due to renal excretion,both in vitro and in vivo experiments demonstrate that Sn nanocluster@CDs may become a promising PS,owning a high potential for application in PDT.展开更多
文摘Background: The segmental multi-frequency bioelectrical impedance analysis (SMF-BIA) is a useful method for evaluating physical health and nutritional status in various clinical settings. But less is known about its role in the preoperative assessment of breast cancer patients. Herein, we try to monitor the changes in body composition of preoperative patients by SMF-BIA and figure out its association with clinical features. Methods: The changes in body composition were monitored by SMF-BIA in 563 female patients with breast cancer. Monitor body moisture and collect relevant data on the day before surgery as a prospective study. Retrospective analysis will be conducted based on preoperative data and pathological results after lymph node resection, Spearman’s correlation coefficients were calculated to investigate the correlation among parameters. Results: We found that the body water, extracellular water ratio, and bioelectrical impedance of the affected upper limbs of patients with different tumor stages or different numbers of lymph node metastases were significantly different from those of their healthy upper limbs (P P P P P Conclusion: SMF-BIA can help monitor the changes in body composition of breast cancer patients and provide detailed information for making a personalized treatment plan and individual nursing schedule. However, the value of SMF-BIA in preoperative assessment still needs to be validated in large prospective clinical trials.
文摘Objective: To investigate the effect of surgical nursing on grade III Hand-Foot Syndrome (HFS) induced by Doxorubicin hydrochloride liposome chemotherapy after breast cancer surgery. Method: From January 2019 to December 2019, 10 patients with HFS grade III caused by Doxorubicin hydrochloride liposome chemotherapy after breast cancer surgery in the Breast Department of Cancer Prevention and Treatment Center of Sun Yat-sen University were selected, and surgical nursing methods were used to intervene and observe the therapeutic effects of the patients. Results: One patient was cured within 7 days, the cure rate was 10% in 7 days, 8 patients were cured within 10 days, the cure rate was 80% in 10 days, 10 patients were cured within 15 days, the cure rate was 100% in 15 days. Conclusion: The surgical nursing method is effective for patients with grade III HFS caused by Doxorubicin hydrochloride liposome chemotherapy after breast cancer surgery, shortening the treatment time of HFS, and is worthy of clinical promotion.
文摘BACKGROUND: Secondary lymphedema is one of the common complications after malignant tumor surgery. It is a chronic and complex disease. Once lymphedema occurs, there will be discomfort such as limb swelling, pain, numbness and tension, which will eventually lead to changes in the appearance of the affected limb and will seriously affect the quality of life and require lifelong treatment and psychosocial support. This study investigated the current situation of stigma and alexithymia in patients with lymphedema, and discussed the impact of alexithymia on stigma in patients with lymphedema. AIMS: To understand the current situation of stigma and alexithymia in patients with lymphedema, and to analyze the influence of alexithymia on stigma. METHODS: 195 patients with lymphedema in a hospital were selected by convenient sampling. General information questionnaire, Toronto Alexithymia Scale and social impact scale were used to investigate respectively, to study the general situation, stigma and alexithymia of the respondents. RESULTS: The results showed that the total score of stigma in 195 patients with lymphedema was (60.36 ± 11.08), and the total score of alexithymia was (56.53 ± 8.43). Multiple linear regression analysis showed that alexithymia and family relationship were the influencing factors of stigma in patients with lymphedema. CONCLUSIONS: The patients with lymphedema have obvious stigma, and alexithymia and family relationship are the influencing factors.
文摘We show that an intrinsically nonlinear oscillator can always be transformed into a linear or harmonic oscillator by addition of a constant force, which shifts the equilibrium position of the oscillator.
文摘Objective: To explore the pre-treatment and efficacy analysis of comprehensive anti-inflammatory treatment for lymphedema in patients with irritating contact dermatitis. Method: Convenience sampling method was used to observe the skin of 160 patients with upper limb lymphedema admitted to the lymphedema outpatient department of our hospital. They were divided into an observation group (80 cases) and a control group (80 cases), and both groups received a course of comprehensive anti-inflammatory treatment (20 treatments). The control group received routine skin care;On the basis of the control group, the observation group received pre-treatment of the affected limb skin: Laofuzi herbal ointment was applied externally to the prone areas of irritating contact dermatitis (such as the upper arm, inner forearm, and cubital fossa). Result: The incidence of irritating contact dermatitis in the observation group was significantly lower than that in the control group (P 0.05). Patients in the observation group felt significantly better in terms of comfort, skin moisture, and itching relief after being wrapped with low elasticity bandages than those in the control group (P Conclusion: Preventive treatment can effectively reduce the incidence of irritating contact dermatitis, prolong the time of stress treatment, thereby increasing efficacy and improving patient compliance.
文摘Objective: The purpose of the study was to explore the application effects of the cloud platform-based comprehensive online management for breast cancer patients using dual-targeted therapy with macromolecular monoclonal antibodies. Methods: 120 breast cancer patients treated by dual-targeted therapy with macromolecular monoclonal antibodies were managed by a cloud platform from March to November 2019. Comprehensive online management included consultation about drugs and side effects and frequently asked questions in the dual-targeted therapy with macromolecular monoclonal antibodies. Results: In the consultation about drugs and side effects, there were five patients with fever, neutrophil, cough, and fatigue;24 with diarrhea;25 with nausea;11 with oral mucosal inflammation;10 with rashes and dry skin;8 with insomnia;and 1 with palpitation. Moreover, 110 patients with anxiety about the missed or delayed treatment were properly handled. Conclusion: The comprehensive online management of dual-targeted therapy with macromolecular monoclonal antibodies based on the cloud platform is helpful to satisfy the at-home breast cancer patients’ needs, ensure the continuity of dual-targeted therapy with macromolecular monoclonal antibodies for breast cancer patients, prevent misinformation, alleviate patients’ negative psychological emotions, and reduce patients’ economic losses. The online cloud platform integrated management model is crucial for managing patients with breast cancer treated by dual-targeted therapy.
基金supported by the National Natural Science Foundation of China (No.20677021)the Science Foundation of Jishou University (No.jsdxkyzz200101)
文摘This study aimed to develop original laboratory culture and sediment toxicity testing protocols for the freshwater gastropod Bellamya aeruginosa (Reeve), a new potential species for sediment toxicity testing. B. aeruginosa was successfully cultured with an effective culture system under proposed laboratory conditions. Optimal ad libitum feeding levels for larvae, juveniles, and adults were 2.0, 6.0, and 16.0 mg fish food/(snall.day), respectively. Mean survival rates of juveniles were higher than 90%, The snails could be sexed at 9 weeks of age, and their generation time is approximately 4 months. Reproduction continued all year around; the mean fecundity was 0.55 newborn/(female.day). The utility of this species for bioassays was evaluated in both 10-day and 28-day case studies with artificial sediments. The 10-day LC50 of Cu for larvae was 480 μg/g dry weight (dw), and the lowest observed effects concentration of Cu for survival and growth of larvae was 195 μg/g dw. Survival and growth are reliable indicators of acute toxicity. Larvae accumulated more Cu than adults. B. aeruginosa exhibited a higher sensitivity to Cu exposure than standard test species (Hyalella azteca and Chironomus tentans). The 28-day test of sediment toxicity with adults showed that fecundity was a robust endpoint indicator of reproductive toxicity, and the biochemical endpoints of superoxide dismutase, catalase, and glutathione could be used as sensitive biomarkers for Cu-induced oxidative damage. B. aeruginosa can be therefore recommended as a candidate for the standardization of the freshwater sediment toxicity test protocol.
基金the Natural Science Foundation of Chongqing, No. 2005(54)
文摘The ventral tegmental area and the locus coeruleus are associated with psychological and physical dependence of opioid addiction. To date, very little is known about brain-derived neurotrophic factor (BDNF) and Bcl-2 gene and protein changes following morphine addiction. The present study utilized immunohistochemistry and in situ hybridization techniques, which revealed that there were increased BDNF levels, but decreased Bcl-2 levels in the prefrontal cortex, locus coeruleus, hippocampus, and the ventral tegmental area during morphine-dependence formation and abstinence. However, the levels of BDNF remained unchanged, and Bcl-2 expression was increased in the nucleus accumbens. These results showed that BDNF and Bcl-2 are involved in the development of morphine dependence, and precipitation of abstinence syndrome.
基金the National Natural Science Foundationof China, No. 30470607
文摘BACKGROUND: The four measures used to assess the stability of the Wisconsin card sorting test (WCST), that is, the number of preservative errors, percentage of preservative errors, number of categories completed, and the number of trials to complete the first category, reflect the function of the frontal lobe. OBJECTIVE: This study was designed to investigate the effects of asthma on the stability of WCST measurements through the use of a twin study, and to analyze whether egg-type difference exists. DESIGN: A cohort study. SETTING: Mental Health Center, the First Affiliated Hospital of Chongqing Medical University. PARTICIPANTS: Fifty-nine pairs of twins, aged 6-16 years, were primarily selected from schools between August 2005 and February 2007 and the WCST and Zygosity identification test was applied. Twins with achromatopsia, severe upper limb diseases, somatic diseases, or mental disorders were excluded. According to disease history of asthmatic attack, children were assigned into asthma (n = 16) and non-asthma (n = 43) groups. METHODS: Four WCST measurements were determined in the 59 pairs of twins, and egg-type differences were identified in conjunction. RESULTS: All 59 pairs of twins were included in the final analysis. Among the pairs of twins, 28 (48.5 %) were monozygotic twins, and 31 (52%) were dizygotic twins. Among the monozygotic and dizygotic twins, the number of preservative errors and percentage of preservative errors were significantly higher in the asthma group than in the non-asthma group (P 〈 0.05). However, there was no significant difference of each corresponding measure between the monozygotic and dizygotic twins (P 〉 0.05). CONCLUSION: Asthma may affect the stability of WCST measures, but egg-type differences do not exist.
文摘The purpose of this research is to investigate the sinuosity of major rivers in the United States and the world, and to compare them to that predicted by the existing theories. It is shown that the average sinuosity of meandering rivers deviates considerably from what has been reported previously as π. Calculations of the mean value of actual sinuosities of major rivers in the United States and in the World show that this average is very close to 2. Exact models as well as a Monte Carlo simulation for meandering rivers that is based on Gaussian probability distribution function are also presented, and the possibility of composite meandering is discussed.
文摘Despite several attempts that have been made to explain the twin paradox, which are based on asymmetry and acceleration, it is shown that none of these explanations can resolve the paradox in the general case. Three specific examples of the twin paradox are provided in which the system is completely symmetric;consequently the existing explanations are not able to resolve the paradox.
基金supported by the National Key Research and Development Program of China(2021YFA1301900,2021YFA1301203 and 2022YFC2303700 to H.D.and Z.S.)the National Natural Science Foundation of China(31900039 and 32170029 to X.T.,81971974 to H.D.,32222040 and 32070049 to Z.S.)+1 种基金the 1.3.5 Project for Disciplines Excellence of West China Hospital,Sichuan University(ZYYC20021 to H.D.)Tianjin Synthetic Biotechnology Innovation Capacity Improvement Action(TSBICIP-KJGG-008 to Z.S.).
文摘CRISPR‒Cas7-11 is a Type Ⅲ-E CRISPR-associated nuclease that functions as a potent RNA editing tool.Tetratrico-peptide repeat fused with Cas/HEF1-associated signal transducer(TPR-CHAT)acts as a regulatory protein that interacts with CRISPR RNA(crRNA)-bound Cas7-11 to form a CRISPR-guided caspase complex(Craspase).However,the precise modulation of Cas7-11’s nuclease activity by TPR-CHAT to enhance its utility requires further study.Here,we report cryo-electron microscopy(cryo-EM)structures of Desulfonema ishimotonii(Di)Cas7-11-crRNA,complexed with or without the full length or the N-terminus of TPR-CHAT.These structures unveil the molecular features of the Craspase complex.Structural analysis,combined with in vitro nuclease assay and electrophoretic mobility shift assay,reveals that DiTPR-CHAT negatively regulates the activity of DiCas7-11 by preventing target RNA from binding through the N-terminal 65 amino acids of DiTPR-CHAT(DiTPR-CHAT_(NTD)).Our work demonstrates that DiTPRCHAT_(NTD) can function as a small unit of DiCas7-11 regulator,potentially enabling safe applications to prevent overcutting and offtarget effects of the CRISPR‒Cas7-11 system.
基金financially supported by the National Natural Science Foundation of China(No.51772001)the support from the Key Laboratory of Structure and Functional Regulation of Hybrid Materials(Anhui University),Ministry of Education,Chinathe Key Laboratory of Environment-Friendly Polymer Materials of Anhui Province,Anhui University。
文摘Recently,photodynamic therapy(PDT)has been extensively applied in clinical and coadjuvant treatment of various kinds of tumors.However,the photosensitizer(PS)of PDT still lack of high production of singlet oxygen(^(1)O_(2)),low cytotoxicity and high biocompatibility.Herein,we propose a facile method for establishing a new core-shell structured Sn nanocluster@carbon dots(CDs)PS.Firstly,Sn^(4+)@S-CDs complex is synthesized using the sulfur-doped CDs(S-CDs)and SnCl4 as raw materials,and subsequently the new PS(Sn nanocluster@CDs)is obtained after vaporization of Sn4+@S-CDs solution.Remarkably,the obtained Sn nanocluster@CDs show an enhanced fluorescence as well as a higher ^(1)O_(2) quantum yield(QY)than S-CDs.The high ^(1)O_(2) QY(58.3%)irradiated by the LED light(400-700 nm,40 mW/cm^(2)),induce the reduction of 4 T1 cancer cells viability by 25%.More intriguingly,no visible damage happens to healthy cells,with little impact on liver tissue due to renal excretion,both in vitro and in vivo experiments demonstrate that Sn nanocluster@CDs may become a promising PS,owning a high potential for application in PDT.