This paper looks back to the development of plant tissue culture in China in the last century. Since 1934, tissue culture studies in China has kept up with the international development in the fields. Progress has bee...This paper looks back to the development of plant tissue culture in China in the last century. Since 1934, tissue culture studies in China has kept up with the international development in the fields. Progress has been made by Chinese in nearly every branches of tissue culture, including in vitro organogenesis, shoot tip culture, anther culture, ovary culture, endosperm culture, protoplast culture as well as mass cell culture. On the basis of reviewing the articles written by Chinese on plant tissue culture, the internationally recognized contributions are specially mentioned. The applications of plant tissue culture to agriculture and industry in China are also introduced.展开更多
The research explored the effects of carbon, nitrogen and inorganic salt nutritional factors on Lactarius deliciosus hyphae as per solid culture. The optimal recipe of culture medium was selected by observing hypha de...The research explored the effects of carbon, nitrogen and inorganic salt nutritional factors on Lactarius deliciosus hyphae as per solid culture. The optimal recipe of culture medium was selected by observing hypha density and computing the growth index, which is the most suitable for hypha growth. The results indicated that glucose and peptone were optimal carbon and nitrogen for Lactarius deliciosus;MgSO4, CuSO4 and VB2 promoted hypha growth; FeSO4 and CoCl2 had inhibition effects. The orthogonal test concluded the optimal recipe contained glucose of 20 g/L, peptone of 1 g/L, KH2PO4 of 0.3 g/L, MgSO4 of 0.3 g/L, VB2 of 2 mg/L, and agar of 20 g/L, with original pH value adopted. After optimization, growth index of hyphae cultured at 28 ℃ was 4 055.9.展开更多
[ Objective] To investigate the feasibility of the primary culture of bovine mammary epithelial cells in biochemical incubator. [ Method] In vitro, bovine mammary epithelial cells were isolated and cultured by the tis...[ Objective] To investigate the feasibility of the primary culture of bovine mammary epithelial cells in biochemical incubator. [ Method] In vitro, bovine mammary epithelial cells were isolated and cultured by the tissue explant method in order to investigate the optimal culture conditions. The morphology observation and identification of the cultured cells were performed by inverted microscope observation, Giemsa staining and cytokeratin immunohistochemistry. [ Result] Observed with inverted microscope, most of the bovine mammary epithelial cells were polygonal and displayed typical slabstone-like appearance. As it can be seen from cell staining results, the cell body was big and the nucleus was stained dark blue and was round or oval in shape, with clearly visible nucleoli, generally 2 -4 nucleoli. The tissue-specific expression of cytokeratin 14 and cytokeratin 18 genes in mammary epithelial cells was identified by cytokeratin immunohistochemistry. [ Conclusion] Primary bovine mammary epithelial cells were successfully cultured in biochemical incubator.展开更多
The requirements of growth and organ development create a challenge in nutritional management of newborn infants,especially premature newborn and intestinal-failure infants.Since their feeding may increase the risk of...The requirements of growth and organ development create a challenge in nutritional management of newborn infants,especially premature newborn and intestinal-failure infants.Since their feeding may increase the risk of necrotizing enterocolitis,some high-risk infants receive a small volume of feeding or parenteral nutrition (PN) without enteral feeding.This review summarizes the current research progress in the nutritional management of newborn infants.Searches of MEDLINE (1998-2007),Cochrane Central Register of Controlled Trials (The Cochrane Library,Issue 3,2007),abstracts and conference proceedings,references from relevant publications in the English language were performed,showing that breast milk is the preferred source of nutrients for enteral feeding of newborn infants.The number of nutrients found in human milk was recommended as a guideline in establishing the minimum and maximum levels in infant formulas.The fear of necrotizing enterocolitis and feeding intolerance are the major factors limiting the use of the enteral route as the primary means of nourishing premature infants.PN may help to meet many of the nutritional needs of these infants,but has significant detrimental side effects.Trophic feedings (small volume of feeding given at the same rate for at least 5 d) during PN are a strategy to enhance the feeding tolerance and decrease the side effects of PN and the time to achieve full feeding.Human milk is a key component of any strategy for enteral nutrition of all infants.However,the amounts of calcium,phosphorus,zinc and other nutrients are inadequate to meet the needs of the very low birth weight (VLBW) infants during growth.Therefore,safe and effective means to fortify human milk are essential to the care of VLBW infants.展开更多
AIM: To investigate the effect of a new infant formula supplemented with a low level (0.24 g/100 mL) of galacto-oligosaccharide (GOS) on intestinal micro-flora (Bif idobacteria, Lactobacilli and E. coli) and fermentat...AIM: To investigate the effect of a new infant formula supplemented with a low level (0.24 g/100 mL) of galacto-oligosaccharide (GOS) on intestinal micro-flora (Bif idobacteria, Lactobacilli and E. coli) and fermentation characteristics in term infants, compared with human milk and a standard infant formula without GOS. METHODS: Term infants (n = 371) were approached in this study in three hospitals of China. All infants started breast-feeding. Those who changed to formula-feeding within 4 wk after birth were randomly assigned to one of the two formula groups. Growth and stool characteristics, and side effects that occurred in recruited infants were recorded in a 3-mo follow-up period. Fecal samples were collected from a subpopulation of recruited infants for analysis of intestinal bacteria (culture technique), acetic acid (gas chromatography) and pH (indicator strip). RESULTS: After 3 mo, the intestinal Bifidobacteria, Lactobacilli , acetic acid and stool frequency were significantly increased, and fecal pH was decreased in infants fed with the GOS-formula or human milk, compared with those fed with the formula withoutGOS. No significant differences were observed between the GOS formula and human milk groups. Supplementation with GOS did not influence the incidence of crying, regurgitation and vomiting. CONCLUSION: A low level of GOS (0.24 g/100 mL) in infant formula can improve stool frequency, decrease fecal pH, and stimulate intestinal Bifidobacteria and Lactobacilli as in those fed with human milk.展开更多
Chronic hepatitis B virus (HBV) infection affects about 350 million individuals worldwide. Management of HBV infection in pregnancy is difficult because of several peculiar and somewhat controversial aspects. The aim ...Chronic hepatitis B virus (HBV) infection affects about 350 million individuals worldwide. Management of HBV infection in pregnancy is difficult because of several peculiar and somewhat controversial aspects. The aim of the present review is to provide a tool that may help physicians to correctly manage HBV infection in pregnancy. This review focuses on (1) the effect of pregnancy on HBV infection and of HBV infection on pregnancy; (2) the potential viral transmission from mother to newborn despite at-birth prophylaxis with immunoglobulin and vaccine; (3) possible prevention of mother-to-child transmission through antiviral drugs, the type of antiviral drug to use considering their efficacy and potential teratogenic effect, and the timing of their administration and discontinuation; and (4) the evidence for the use of elective caesarean section vs vaginal delivery and the possibility of breastfeeding.展开更多
Objectives:To examine the efficacy of an intervention based on the theory of planned behavior(TPB)in improving breastfeeding behavior among women with cesarean sections(C-sections).Methods:This research was a randomiz...Objectives:To examine the efficacy of an intervention based on the theory of planned behavior(TPB)in improving breastfeeding behavior among women with cesarean sections(C-sections).Methods:This research was a randomized controlled trial.Women with planned elective C-sections were recruited to participate in a randomized controlled trial between June and September 2020.One hundred thirty-two women were divided randomly into the intervention(n=66)and control group(n=66)by systematic random sampling.In the intervention group,an intervention project was implemented after Keywords:Breastfeeding Cesarean section Intervention studies Theory of planned behavior the C-section to establish positive breastfeeding attitudes,cultivate supportive subjective norms,enhance perceived behavioral control,and strengthen breastfeeding intention to change behaviors.Those in the control group received routine pre-and post-delivery care.Exclusive breastfeeding rate and breast problem were collected at 5 days,2 weeks,and 1 month after C-section.The modified Breastfeeding Attrition Prediction Tool(BAPT)on the first day in the hospital,two weeks,and one month after C-section and Numerical Rating Scale(NRS)24 h postoperatively were used to compare the intervention effect between the two groups.Results:After the intervention,the intervention group had significantly higher exclusive breastfeeding rates than the control group at five days(86.4%vs.60.6%),two weeks(77.3%vs.57.6%),and one month(74.2%vs.50.0%)after the C-section.Besides,the intervention group was less likely to have sore nipples at five days(6.1%vs.18.2%in the control group,P<0.05)and two weeks(9.1%vs.12.1%in the control group,P<0.05).After two weeks of intervention,attitude scores(90.64±8.31 vs.87.20±8.15,P<0.05),subjective norm scores(88.07±24.65 vs.79.42±19.47,P<0.05)and behavior control scores in the intervention group were significantly higher than those in the control group.After one month of intervention,attitude scores(90.34±10.35 vs.84.22±10.51,P<0.05)and behavior control scores(43.13±5.02 vs.39.15±4.69,P<0.05)in the intervention group were significantly higher than those in the control group,which resulted in the higher breastfeeding intention in the intervention group.Conclusion:This study indicated that the TPB-based interventions effectively improved women's breastfeeding behaviors after C-sections.展开更多
Objectives:To explore the factors affecting breastfeeding behaviors in women after cesarean section.Methods:This is a qualitative study that used a phenomenological approach.This study used individual face-to-face int...Objectives:To explore the factors affecting breastfeeding behaviors in women after cesarean section.Methods:This is a qualitative study that used a phenomenological approach.This study used individual face-to-face interviews with 19 women who underwent a cesarean section in a Women and Children’s Hospital in China between July to September 2019.Information saturationwas used to determine sample size.Data were analyzed using a thematic content analysis method.Themes were developed based on the theory of planned behavior.Results:Thirteen(68.42%)had a planned cesarean section,and six(31.58%)cesarean sections were unplanned or emergent.Three major themes emerged:ambivalent attitude about breastfeeding,motivation to comply with the traditional cultural norms,and barriers and challenges.The motivating factors for breastfeeding after cesarean sections included perceived benefits of human milk,support from healthcare professionals,and responsibility for breastfeeding.The challenges for breastfeeding after cesarean sections included physical discomfort,knowledge and skills deficit of breastfeeding,lactation deficiency,and lack of knowledge and coping skills in managing their depressive mood after cesarean sections.There were a couple of neutral factors,such as the influences of family and peers.These factors could influence women either positively as facilitators or negatively as barriers.Conclusions:The findings can offer valuable information for healthcare professionals to help women breastfeed after cesarean sections.To promote women’s breastfeeding behaviors after cesarean sections,it is necessary to change women’s attitudes,belief systems,and the external environments and help them become more confident.展开更多
Objective:To observe the changing of biomechanical features during the degradation course of poly-D,L-lactic acid (PDLLA) rods in vivo and in vitro and to evaluate its value as an internal fixation material. Metho...Objective:To observe the changing of biomechanical features during the degradation course of poly-D,L-lactic acid (PDLLA) rods in vivo and in vitro and to evaluate its value as an internal fixation material. Methods :PDLLA rods were emerged into PBS simultaneous body fluid with constant temperature of 37℃ and the rods were embedded into muscle tissue of 20 rabbits for degradation in vitro and in vivo . The rods were taken out in 2, 4, 6, 8 and 12 weeks. Biomechanical features of bending, shearing and axial compression strength, rigidity and elastic modulus were observed during the degradation course. Statistical method was used to test the changes of biomechanical parameters. Results: (1)There was similar changes of bending, compressive, shearing strength and bending, compressive and shearing rigidity of the PDLLA rods between in vivo and in vitro. (2)Bending, compressive, shearing strength decreased 33%, 18 % and 43 % respectively within the first stage of the degradation, and after 6 weeks of degradation, they decreased slowly. (3)Elastic modulus, bending, compressive and shearing rigidity.decreased sharply during the 6 weeks of degradation, with a drop of 22%, 39% and 30% respectively, and after 8 weeks, they decreased slowly. Even after 12 weeks of degradation, the strength of the rods was still higher than that of sponge bone. Conclusion: During the degradation of the material, the strength and rigidity of PDLLA rods can meet the need of fracture fixation of cancellous bones.展开更多
Objective:This study aimed to gain an in-depth understanding of the experience of South African working mothers in the adherence to exclusive breastfeeding when returning from maternity leave.Methods:The data of the s...Objective:This study aimed to gain an in-depth understanding of the experience of South African working mothers in the adherence to exclusive breastfeeding when returning from maternity leave.Methods:The data of the study was collected using face-to-face semi-structured interviews.Eight breastfeeding mothers were purposefully selected from two primary health care clinics in Rustenburg,North West Province,South Africa.The data were coded,categorized,and clustered into themes using Giorgi’s phenomenological analysis.Ethical considerations and measures of trustworthiness were adhered to throughout the study.Results:The findings revealed three themes:a desire for working mothers to continue the adherence to exclusive breastfeeding,workplace support for breastfeeding mothers in the adherence to exclusive breastfeeding,and an unsuitable workplace environment for the adherence to exclusive breastfeeding.Six sub-themes were identified:the need to return to the workplace soon after baby’s birth,psychological responses in the adherence to exclusive breastfeeding,lack of support from employers and coworkers in the adherence to exclusive breastfeeding,lack of or partial implementation of breastfeeding policies in the workplace,the workplace not being supportive for mothers’having to express and the workplace not being supportive for mothers’having to store breastmilk.Conclusion:Based on the findings,South African government should revisit employment policies to support working mothers who need to continue with exclusive breastfeeding after returning from maternity leave.展开更多
Objective: To investigate the association between breastfeeding and infant acquired infection of Hepatitis C Virus(HCV). Methods: To obtain studies eligible for META-analysis, China biological medicine discs(CBMD) and...Objective: To investigate the association between breastfeeding and infant acquired infection of Hepatitis C Virus(HCV). Methods: To obtain studies eligible for META-analysis, China biological medicine discs(CBMD) and MEDLINE citations were surveyed. Criteria for enrollment of published studies for META-analysis were based on principle by Abdolmaleky HM[1]. Odd ratio(OR) was calculated and summarized by fixed effect model or random effects using RevMan software. The heterogeneity of ORs was assessed using an χ2 test of goodness of fit. The significance of the pooled OR was determined by the z-test. The strength of association was summarized usingOR. An OR>1.0 indicated a positive association between the risk factor and infants HCV infection. Results:After searching in Medline and CBMD, 120 articles were enrolled for further identification. Thirty-seven were of review on relative fields and were excluded. Abstracts of remaining articles were carefully read, and finally, only 6 articles met, the standards for enrollment criteria. After analysis of the factor concerned, no significant association was found between breastfeeding and infant HCV infection, with a pooled OR equal to 0.60(95%CI = 0.22-1.60), and proved not to be of risk factors on infant acquired infection of HCV. Conclusion: Breastfeeding dose not increase the risk of infant acquired infection of HCV.展开更多
文摘This paper looks back to the development of plant tissue culture in China in the last century. Since 1934, tissue culture studies in China has kept up with the international development in the fields. Progress has been made by Chinese in nearly every branches of tissue culture, including in vitro organogenesis, shoot tip culture, anther culture, ovary culture, endosperm culture, protoplast culture as well as mass cell culture. On the basis of reviewing the articles written by Chinese on plant tissue culture, the internationally recognized contributions are specially mentioned. The applications of plant tissue culture to agriculture and industry in China are also introduced.
基金Supported by the Doctoral Scientific Research Foundation of Jiangxi Agricultural University(09004659)~~
文摘The research explored the effects of carbon, nitrogen and inorganic salt nutritional factors on Lactarius deliciosus hyphae as per solid culture. The optimal recipe of culture medium was selected by observing hypha density and computing the growth index, which is the most suitable for hypha growth. The results indicated that glucose and peptone were optimal carbon and nitrogen for Lactarius deliciosus;MgSO4, CuSO4 and VB2 promoted hypha growth; FeSO4 and CoCl2 had inhibition effects. The orthogonal test concluded the optimal recipe contained glucose of 20 g/L, peptone of 1 g/L, KH2PO4 of 0.3 g/L, MgSO4 of 0.3 g/L, VB2 of 2 mg/L, and agar of 20 g/L, with original pH value adopted. After optimization, growth index of hyphae cultured at 28 ℃ was 4 055.9.
基金Supported by Natural Science Foundation of Inner Mongolia Autono-mous Region (200711020407)China Agricultural University and Inner Mongolia Agricultural University Cooperation Projects~~
文摘[ Objective] To investigate the feasibility of the primary culture of bovine mammary epithelial cells in biochemical incubator. [ Method] In vitro, bovine mammary epithelial cells were isolated and cultured by the tissue explant method in order to investigate the optimal culture conditions. The morphology observation and identification of the cultured cells were performed by inverted microscope observation, Giemsa staining and cytokeratin immunohistochemistry. [ Result] Observed with inverted microscope, most of the bovine mammary epithelial cells were polygonal and displayed typical slabstone-like appearance. As it can be seen from cell staining results, the cell body was big and the nucleus was stained dark blue and was round or oval in shape, with clearly visible nucleoli, generally 2 -4 nucleoli. The tissue-specific expression of cytokeratin 14 and cytokeratin 18 genes in mammary epithelial cells was identified by cytokeratin immunohistochemistry. [ Conclusion] Primary bovine mammary epithelial cells were successfully cultured in biochemical incubator.
文摘The requirements of growth and organ development create a challenge in nutritional management of newborn infants,especially premature newborn and intestinal-failure infants.Since their feeding may increase the risk of necrotizing enterocolitis,some high-risk infants receive a small volume of feeding or parenteral nutrition (PN) without enteral feeding.This review summarizes the current research progress in the nutritional management of newborn infants.Searches of MEDLINE (1998-2007),Cochrane Central Register of Controlled Trials (The Cochrane Library,Issue 3,2007),abstracts and conference proceedings,references from relevant publications in the English language were performed,showing that breast milk is the preferred source of nutrients for enteral feeding of newborn infants.The number of nutrients found in human milk was recommended as a guideline in establishing the minimum and maximum levels in infant formulas.The fear of necrotizing enterocolitis and feeding intolerance are the major factors limiting the use of the enteral route as the primary means of nourishing premature infants.PN may help to meet many of the nutritional needs of these infants,but has significant detrimental side effects.Trophic feedings (small volume of feeding given at the same rate for at least 5 d) during PN are a strategy to enhance the feeding tolerance and decrease the side effects of PN and the time to achieve full feeding.Human milk is a key component of any strategy for enteral nutrition of all infants.However,the amounts of calcium,phosphorus,zinc and other nutrients are inadequate to meet the needs of the very low birth weight (VLBW) infants during growth.Therefore,safe and effective means to fortify human milk are essential to the care of VLBW infants.
文摘AIM: To investigate the effect of a new infant formula supplemented with a low level (0.24 g/100 mL) of galacto-oligosaccharide (GOS) on intestinal micro-flora (Bif idobacteria, Lactobacilli and E. coli) and fermentation characteristics in term infants, compared with human milk and a standard infant formula without GOS. METHODS: Term infants (n = 371) were approached in this study in three hospitals of China. All infants started breast-feeding. Those who changed to formula-feeding within 4 wk after birth were randomly assigned to one of the two formula groups. Growth and stool characteristics, and side effects that occurred in recruited infants were recorded in a 3-mo follow-up period. Fecal samples were collected from a subpopulation of recruited infants for analysis of intestinal bacteria (culture technique), acetic acid (gas chromatography) and pH (indicator strip). RESULTS: After 3 mo, the intestinal Bifidobacteria, Lactobacilli , acetic acid and stool frequency were significantly increased, and fecal pH was decreased in infants fed with the GOS-formula or human milk, compared with those fed with the formula withoutGOS. No significant differences were observed between the GOS formula and human milk groups. Supplementation with GOS did not influence the incidence of crying, regurgitation and vomiting. CONCLUSION: A low level of GOS (0.24 g/100 mL) in infant formula can improve stool frequency, decrease fecal pH, and stimulate intestinal Bifidobacteria and Lactobacilli as in those fed with human milk.
文摘Chronic hepatitis B virus (HBV) infection affects about 350 million individuals worldwide. Management of HBV infection in pregnancy is difficult because of several peculiar and somewhat controversial aspects. The aim of the present review is to provide a tool that may help physicians to correctly manage HBV infection in pregnancy. This review focuses on (1) the effect of pregnancy on HBV infection and of HBV infection on pregnancy; (2) the potential viral transmission from mother to newborn despite at-birth prophylaxis with immunoglobulin and vaccine; (3) possible prevention of mother-to-child transmission through antiviral drugs, the type of antiviral drug to use considering their efficacy and potential teratogenic effect, and the timing of their administration and discontinuation; and (4) the evidence for the use of elective caesarean section vs vaginal delivery and the possibility of breastfeeding.
文摘Objectives:To examine the efficacy of an intervention based on the theory of planned behavior(TPB)in improving breastfeeding behavior among women with cesarean sections(C-sections).Methods:This research was a randomized controlled trial.Women with planned elective C-sections were recruited to participate in a randomized controlled trial between June and September 2020.One hundred thirty-two women were divided randomly into the intervention(n=66)and control group(n=66)by systematic random sampling.In the intervention group,an intervention project was implemented after Keywords:Breastfeeding Cesarean section Intervention studies Theory of planned behavior the C-section to establish positive breastfeeding attitudes,cultivate supportive subjective norms,enhance perceived behavioral control,and strengthen breastfeeding intention to change behaviors.Those in the control group received routine pre-and post-delivery care.Exclusive breastfeeding rate and breast problem were collected at 5 days,2 weeks,and 1 month after C-section.The modified Breastfeeding Attrition Prediction Tool(BAPT)on the first day in the hospital,two weeks,and one month after C-section and Numerical Rating Scale(NRS)24 h postoperatively were used to compare the intervention effect between the two groups.Results:After the intervention,the intervention group had significantly higher exclusive breastfeeding rates than the control group at five days(86.4%vs.60.6%),two weeks(77.3%vs.57.6%),and one month(74.2%vs.50.0%)after the C-section.Besides,the intervention group was less likely to have sore nipples at five days(6.1%vs.18.2%in the control group,P<0.05)and two weeks(9.1%vs.12.1%in the control group,P<0.05).After two weeks of intervention,attitude scores(90.64±8.31 vs.87.20±8.15,P<0.05),subjective norm scores(88.07±24.65 vs.79.42±19.47,P<0.05)and behavior control scores in the intervention group were significantly higher than those in the control group.After one month of intervention,attitude scores(90.34±10.35 vs.84.22±10.51,P<0.05)and behavior control scores(43.13±5.02 vs.39.15±4.69,P<0.05)in the intervention group were significantly higher than those in the control group,which resulted in the higher breastfeeding intention in the intervention group.Conclusion:This study indicated that the TPB-based interventions effectively improved women's breastfeeding behaviors after C-sections.
基金We thank all the mothers who participated in this study.
文摘Objectives:To explore the factors affecting breastfeeding behaviors in women after cesarean section.Methods:This is a qualitative study that used a phenomenological approach.This study used individual face-to-face interviews with 19 women who underwent a cesarean section in a Women and Children’s Hospital in China between July to September 2019.Information saturationwas used to determine sample size.Data were analyzed using a thematic content analysis method.Themes were developed based on the theory of planned behavior.Results:Thirteen(68.42%)had a planned cesarean section,and six(31.58%)cesarean sections were unplanned or emergent.Three major themes emerged:ambivalent attitude about breastfeeding,motivation to comply with the traditional cultural norms,and barriers and challenges.The motivating factors for breastfeeding after cesarean sections included perceived benefits of human milk,support from healthcare professionals,and responsibility for breastfeeding.The challenges for breastfeeding after cesarean sections included physical discomfort,knowledge and skills deficit of breastfeeding,lactation deficiency,and lack of knowledge and coping skills in managing their depressive mood after cesarean sections.There were a couple of neutral factors,such as the influences of family and peers.These factors could influence women either positively as facilitators or negatively as barriers.Conclusions:The findings can offer valuable information for healthcare professionals to help women breastfeed after cesarean sections.To promote women’s breastfeeding behaviors after cesarean sections,it is necessary to change women’s attitudes,belief systems,and the external environments and help them become more confident.
文摘Objective:To observe the changing of biomechanical features during the degradation course of poly-D,L-lactic acid (PDLLA) rods in vivo and in vitro and to evaluate its value as an internal fixation material. Methods :PDLLA rods were emerged into PBS simultaneous body fluid with constant temperature of 37℃ and the rods were embedded into muscle tissue of 20 rabbits for degradation in vitro and in vivo . The rods were taken out in 2, 4, 6, 8 and 12 weeks. Biomechanical features of bending, shearing and axial compression strength, rigidity and elastic modulus were observed during the degradation course. Statistical method was used to test the changes of biomechanical parameters. Results: (1)There was similar changes of bending, compressive, shearing strength and bending, compressive and shearing rigidity of the PDLLA rods between in vivo and in vitro. (2)Bending, compressive, shearing strength decreased 33%, 18 % and 43 % respectively within the first stage of the degradation, and after 6 weeks of degradation, they decreased slowly. (3)Elastic modulus, bending, compressive and shearing rigidity.decreased sharply during the 6 weeks of degradation, with a drop of 22%, 39% and 30% respectively, and after 8 weeks, they decreased slowly. Even after 12 weeks of degradation, the strength of the rods was still higher than that of sponge bone. Conclusion: During the degradation of the material, the strength and rigidity of PDLLA rods can meet the need of fracture fixation of cancellous bones.
文摘Objective:This study aimed to gain an in-depth understanding of the experience of South African working mothers in the adherence to exclusive breastfeeding when returning from maternity leave.Methods:The data of the study was collected using face-to-face semi-structured interviews.Eight breastfeeding mothers were purposefully selected from two primary health care clinics in Rustenburg,North West Province,South Africa.The data were coded,categorized,and clustered into themes using Giorgi’s phenomenological analysis.Ethical considerations and measures of trustworthiness were adhered to throughout the study.Results:The findings revealed three themes:a desire for working mothers to continue the adherence to exclusive breastfeeding,workplace support for breastfeeding mothers in the adherence to exclusive breastfeeding,and an unsuitable workplace environment for the adherence to exclusive breastfeeding.Six sub-themes were identified:the need to return to the workplace soon after baby’s birth,psychological responses in the adherence to exclusive breastfeeding,lack of support from employers and coworkers in the adherence to exclusive breastfeeding,lack of or partial implementation of breastfeeding policies in the workplace,the workplace not being supportive for mothers’having to express and the workplace not being supportive for mothers’having to store breastmilk.Conclusion:Based on the findings,South African government should revisit employment policies to support working mothers who need to continue with exclusive breastfeeding after returning from maternity leave.
基金Supported by National Natural Science Foundation of China(No3 0 2 3 0 3 2 0 ,3 0 671764
文摘Objective: To investigate the association between breastfeeding and infant acquired infection of Hepatitis C Virus(HCV). Methods: To obtain studies eligible for META-analysis, China biological medicine discs(CBMD) and MEDLINE citations were surveyed. Criteria for enrollment of published studies for META-analysis were based on principle by Abdolmaleky HM[1]. Odd ratio(OR) was calculated and summarized by fixed effect model or random effects using RevMan software. The heterogeneity of ORs was assessed using an χ2 test of goodness of fit. The significance of the pooled OR was determined by the z-test. The strength of association was summarized usingOR. An OR>1.0 indicated a positive association between the risk factor and infants HCV infection. Results:After searching in Medline and CBMD, 120 articles were enrolled for further identification. Thirty-seven were of review on relative fields and were excluded. Abstracts of remaining articles were carefully read, and finally, only 6 articles met, the standards for enrollment criteria. After analysis of the factor concerned, no significant association was found between breastfeeding and infant HCV infection, with a pooled OR equal to 0.60(95%CI = 0.22-1.60), and proved not to be of risk factors on infant acquired infection of HCV. Conclusion: Breastfeeding dose not increase the risk of infant acquired infection of HCV.