BACKGROUND IgG4-related disease(IgG4-RD)is a chronic fibrotic disease mediated by immunity recognized by clinicians in recent years.When the kidney is involved,it is called IgG4-related kidney disease(IgG4-RKD).IgG4-r...BACKGROUND IgG4-related disease(IgG4-RD)is a chronic fibrotic disease mediated by immunity recognized by clinicians in recent years.When the kidney is involved,it is called IgG4-related kidney disease(IgG4-RKD).IgG4-related tubulointerstitial nephritis(IgG4-TIN)is a representative manifestation of IgG4-RKD.IgG4-TIN can cause obstructive nephropathy complicated by retroperitoneal fibrosis(RPF).Cases of IgG4-TIN complicated with RPF are rare.Glucocorticoids are the firstline therapeutic medication for IgG4-RD and can significantly improve renal function.CASE SUMMARY Herein,we report the case of a 56-year-old man with IgG4-RKD complicated with RPF.The patient presented to the hospital with complaints of elevated serum creatinine(Cr),nausea,and vomiting.During hospitalization,Cr was 1448.6μmol/L,and serum IgG4 was increased.A total abdominal computed tomography(CT)scan and enhanced CT scan obviously indicated RPF.Although this patient had a long course and renal insufficiency,we performed a kidney biopsy.Renal biopsy showed that the renal tubulointerstitium had focal plasma cell infiltration and increased lymphocyte infiltration accompanied by fibrosis.After combining the biopsy results with immunohistochemistry,it was found that the absolute number of positive IgG4+cells per high power field exceeded 10,and the ratio of IgG4/IgG was over 40%.Finally,the patient was diagnosed with IgG4-TIN complicated with RPF and given glucocorticoids as long-term maintenance therapy,helping him keep out of dialysis.After a follow-up of 19 mo,the patient had recovered well.Previous literature on IgG4-RKD and RPF was retrieved from PubMed to characterize the clinical and pathological features and to identify the diagnosis and treatment of IgG4-RKD.CONCLUSION Our case report demonstrates the clinical characteristics of IgG4-RKD complicated with RPF.Serum IgG4 is a favorable indicator for screening.Performing renal biopsy actively plays a vital role in diagnosis and treatment,even if the patient has a long course and manifests with renal insufficiency.It is remarkable to treat IgG4-RKD with glucocorticoids.Hence,early diagnosis and targeted therapy are essential for reversing renal function and improving extrarenal manifestations in patients with IgG4-RKD.展开更多
Coxsackie virus A16(CA16) is commonly recognized as one of the main human pathogens of hand-foot-mouth disease(HFMD). The clinical manifestations of HFMD include vesicles of hand, foot and mouth in young children and ...Coxsackie virus A16(CA16) is commonly recognized as one of the main human pathogens of hand-foot-mouth disease(HFMD). The clinical manifestations of HFMD include vesicles of hand, foot and mouth in young children and severe inflammatory CNS lesions. In this study, experimentally CA16 infected tree shrews(Tupaia belangeri) were used to investigate CA16 pathogenesis. The results showed that both the body temperature and the percentages of blood neutrophilic granulocytes / monocytes of CA16 infected tree shrews increased at 4-7 days post infection. Dynamic distributions of CA16 in different tissues and stools were found at different infection stages. Moreover, the pathological changes in CNS and other organs were also observed. These findings indicate that tree shrews can be used as a viable animal model to study CA16 infection.展开更多
BACKGROUND No guideline recommends antiviral therapy for hepatitis B e antigen(HBeAg)-positive chronic hepatitis B patients with persistently normal alanine aminotransferase levels and a high hepatitis B virus(HBV)DNA...BACKGROUND No guideline recommends antiviral therapy for hepatitis B e antigen(HBeAg)-positive chronic hepatitis B patients with persistently normal alanine aminotransferase levels and a high hepatitis B virus(HBV)DNA viral load.AIM To evaluate the feasibility and safety of a Chinese herbal formula as a therapeutic option for chronic HBV infection.METHODS In total,395 patients(30–65 years old)with confirmed HBeAg-positive chronic hepatitis B infection and persistently normal alanine aminotransferase were randomized to receive either Chinese herbal formula or placebo for 96 wk.Endpoints to evaluate therapeutic efficacy included:(1)HBV DNA levels decreased to less than 4 log10 IU/mL at weeks 48 and 96;and(2)HBeAg clearance and seroconversion rates at weeks 48 and 96.RESULTS HBV DNA levels≤4 log10 IU/mL were 10.05%at week 48 and 18.59%at week 96 in the treatment group.The HBeAg clearance and conversion rates were 8.54%and 8.04%at week 48 and 16.08%and 14.57%at week 96,respectively.However,HBV DNA levels≤4 log10 IU/mL were 2.55%and 2.55%at weeks 48 and 96,respectively,and the HBeAg clearance rates were 3.06%and 5.61%at weeks 48 and 96,respectively,in the control group.The quantitative hepatitis B surface antigen and HBeAg levels at baseline and changes during the treatment period as well as the alanine aminotransferase elevation at weeks 12 and 24 were strong predictors of HBeAg clearance.CONCLUSION High rates of HBV DNA reduction,HBeAg clearance and seroconversion could be achieved with Chinese herbal formula treatments,and the treatments were relatively safe for HBeAg-positive chronic hepatitis B-infected patients with persistently normal alanine aminotransferase.The ability of the compound to modulate host immune function probably contributed to this effect.展开更多
The Sindbis-like virus was first discovered in China in 1986. Its complete genomic sequence consists of more than 11 000 bp encoding more than 3 700 amino acids. It contains a 5' non-transcriptional region (5'-NTR...The Sindbis-like virus was first discovered in China in 1986. Its complete genomic sequence consists of more than 11 000 bp encoding more than 3 700 amino acids. It contains a 5' non-transcriptional region (5'-NTR) in a non-structural region, four non-structural proteins (nsP1, nsP2, nsP3, nsP4) regions, capsids in conserved and non-conserved regions and structural El, E2, E3, 6K regions and a 3' non-transcriptional region (3'-NTR). The Sindbis-IMB was isolated from the blood of a patient suspected to have encephalitis, and was followed by identification and passage. The virus RNA was extracted from virus supernatant in infected cells and the whole genome was divided into 12 fragments; RT-PCR was then performed to amplify the 12 fragments for complete sequencing. The results showed that the whole genomic sequence of Sindbis-IMB consists of 11 717 bp encoding 3 773 amino acids. Homology comparison with other Sindbis-like isolates demonstrated the highest similarity was the YN87448 with a variation of 1% strain isolated in Yunnan Province and the second highest to the SAAR86 strain with a variation of -1.2%. The nucleotide sequence variations were present in non-structural regions, resulting in amino acids K, E, N, R, H, and L in protein sequences in positions 230, 231,443,781, 1 582, and 1746 in the new isolation respectively. Furthermore, three additional amino acids-glutamic acid, serine and alanine-were noted in nsp4 terminus as compared to the YN87448 isolate展开更多
The form of timing residuals due to errors in pulsar spin period P and its derivative P, in positions, as well as in proper motions, has been well presented for decades in the literature. However,the residual patterns...The form of timing residuals due to errors in pulsar spin period P and its derivative P, in positions, as well as in proper motions, has been well presented for decades in the literature. However,the residual patterns due to errors in the pulsar acceleration have not been reported previously, while a pulsar in the Galaxy or a globular cluster(GC) will be unavoidably accelerated. The coupling effect of the pulsar transverse acceleration and the R¨omer delay on timing residuals is simulated in this work. The results demonstrate that the residuals due to the effect can be identified by the oscillation envelopes of the residuals. It is also shown that the amplitude of the residuals due to the effect is usually relatively small,however, it may probably be observable for pulsars distributed in the vicinity of the core of a nearby GC.展开更多
Meta-heuristics typically takes long time to search optimality from huge amounts of data samples for applications like communication, medicine, and civil engineering. Therefore, parallelizing meta-heuristics to massiv...Meta-heuristics typically takes long time to search optimality from huge amounts of data samples for applications like communication, medicine, and civil engineering. Therefore, parallelizing meta-heuristics to massively reduce runtime is one hot topic in related research. In this paper, we propose a MapReduce modified cuckoo search (MRMCS), an efficient modified cuckoo search (MCS) implementation on a MapReduce architecture--Hadoop. MapReduce particle swarm optimization (MRPSO) from a previous work is also implemented for comparison. Four evaluation functions and two engineering design problems are used to conduct experiments. As a result, MRMCS shows better convergence in obtaining optimality than MRPSO with two to four times speed-up.展开更多
The acceleration of LMXB 4U 1820-30 derived from its orbital-period derivative P_(b)was supposed to be the evidence for an Intermediate-mass black hole(IMBH)in the Galactic globular cluster(GC)NGC 6624.However,we find...The acceleration of LMXB 4U 1820-30 derived from its orbital-period derivative P_(b)was supposed to be the evidence for an Intermediate-mass black hole(IMBH)in the Galactic globular cluster(GC)NGC 6624.However,we find that the anomalous P_(b)is mainly due to the gravitational wave emission,rather than the acceleration in cluster potential.Using the standard structure models of GCs,we simulate acceleration distributions for pulsars in the central region of the cluster.By fitting the acceleration of J1823-3021 A with the simulated distribution profiles(maximum values),it is suggested that an IMBH with mass M■950_(-350)^(+550)M_(⊙) may reside in the cluster center.We further show that the second period derivative P of J1823-3021 A is probably due to the gravitational perturbation of a nearby star.展开更多
We investigate pulsar timing residuals due to the coupling effect of the pulsar transverse acceleration and the Romer delay.The effect is relatively small and usually negligible.Only for pulsars in globular clusters,i...We investigate pulsar timing residuals due to the coupling effect of the pulsar transverse acceleration and the Romer delay.The effect is relatively small and usually negligible.Only for pulsars in globular clusters,it is possibly important.The maximum residual amplitude,which is from the pulsar near the surface of the core of the cluster,is about tens of nanoseconds,and may hardly be identified for most globular clusters currently.However,an intermediate-mass black hole in the center of a cluster can apparently increase the timing residual magnitudes.Particularly for pulsars in the innermost core region,their residual magnitudes may be significant.The high-magnitude residuals,which are above critical lines of each cluster,are strong evidence for the presence of a black hole or dark remnants of comparable total mass in the center of the cluster.We also explored the timing effects of line-of-sight accelerations for the pulsars.The distribution of measured line-of-sight accelerations are simulated with a Monte Carlo method.Two-dimensional Kolmogorov-Smirnov tests are performed to reexamine the consistency of distributions of the simulated and reported data for various values of parameters of the clusters.It is shown that the structure parameters of Terzan 5 can be constrained well by comparing the distribution of measured lineof-sight accelerations with the distributions from Monte Carlo simulations.We find that the cluster has an upper limit on the central black hole/dark remnant mass of~6000 M⊙.展开更多
Enterovirus 71 (EV71) can cause serious nervous system lesions but to date the pathogenesis has been unclear. Our results show that EV71 proliferates in the neural cells and leads to neural cell lesions. The study of ...Enterovirus 71 (EV71) can cause serious nervous system lesions but to date the pathogenesis has been unclear. Our results show that EV71 proliferates in the neural cells and leads to neural cell lesions. The study of the pathology of EV71 infection in neonatal rat brains shows that the invasive ability of EV71 to the nervous system in vivo may depend on many unknown factors.展开更多
This paper considers the empirical Bayes (EB) estimation problem for the parameter β of the linear regression model y = Xβ+ ε with ε- N(0, σ^2I) given β. Based on Pitman closeness (PC) criterion and mean ...This paper considers the empirical Bayes (EB) estimation problem for the parameter β of the linear regression model y = Xβ+ ε with ε- N(0, σ^2I) given β. Based on Pitman closeness (PC) criterion and mean square error matrix (MSEM) criterion, we prove the superiority of the EB estimator over the ordinary least square estimator (OLSE).展开更多
In the system of m (m ≥ 2) seemingly unrelated regressions, we show that the Gauss-Markov estimator (GME) of any regression coefficients has unique simplified form, which exactly equals to the one- step covarianc...In the system of m (m ≥ 2) seemingly unrelated regressions, we show that the Gauss-Markov estimator (GME) of any regression coefficients has unique simplified form, which exactly equals to the one- step covariance-adjusted estimator of the regression coefficients, and hence we conclude that for any finite k ≥ 2 the k-step covariance-adjusted estimator degenerates to the one-step covariance-adjusted estimator and the corresponding two-stage Aitken estimator has exactly one simplified form. Also, the unique simplified expression of the GME is just the estimator presented in the Theorem 1 of Wang' work [1988]. A new estimate of regression coefficients in seemingly unrelated regression system, Science in China, Series A 10, 1033-1040].展开更多
Background Fournier’s gangrene(FG)is a rare life-threatening form of necrotizing fasciitis.The risk factors for septic shock in patients with FG are unclear.This study aimed to identify potential risk factors and dev...Background Fournier’s gangrene(FG)is a rare life-threatening form of necrotizing fasciitis.The risk factors for septic shock in patients with FG are unclear.This study aimed to identify potential risk factors and develop a prediction model for septic shock in patients with FG.Methods This retrospective cohort study included patients who were treated for FG between May 2013 and May 2020 at the Sixth Affiliated Hospital,Sun Yat-sen University(Guangzhou,China).The patients were divided into a septic shock group and a non-septic shock group.An L1-penalized logistic regression model was used to detect the main effect of important factors and a penalized Quadratic Discriminant Analysis method was used to identify possible interaction effects between different factors.The selected main factors and interactions were used to obtain a logistic regression model based on the Bayesian information criterion.Results A total of 113 patients with FG were enrolled and allocated to the septic shock group(n=24)or non-septic shock group(n=89).The best model selected identified by backward logistic regression based on Bayesian information criterion selected temperature,platelets,total bilirubin(TBIL)level,and pneumatosis on pelvic computed tomography/magnetic resonance images as the main linear effect and Na^(+)×TBIL as the interaction effect.The area under the ROC curve of the probability of FG with septic shock by our model was 0.84(95%confidence interval,0.78–0.95).The Harrell’s concordance index for the nomogramwas 0.864(95%confidence interval,0.78–0.95).Conclusion We have developed a prediction model for evaluation of the risk of septic shock in patients with FG that could assist clinicians in identifying critically ill patients with FG and prevent them from reaching a crisis state.展开更多
基金Supported by the Introduction of High-level Health Team Project in Zhuhai.
文摘BACKGROUND IgG4-related disease(IgG4-RD)is a chronic fibrotic disease mediated by immunity recognized by clinicians in recent years.When the kidney is involved,it is called IgG4-related kidney disease(IgG4-RKD).IgG4-related tubulointerstitial nephritis(IgG4-TIN)is a representative manifestation of IgG4-RKD.IgG4-TIN can cause obstructive nephropathy complicated by retroperitoneal fibrosis(RPF).Cases of IgG4-TIN complicated with RPF are rare.Glucocorticoids are the firstline therapeutic medication for IgG4-RD and can significantly improve renal function.CASE SUMMARY Herein,we report the case of a 56-year-old man with IgG4-RKD complicated with RPF.The patient presented to the hospital with complaints of elevated serum creatinine(Cr),nausea,and vomiting.During hospitalization,Cr was 1448.6μmol/L,and serum IgG4 was increased.A total abdominal computed tomography(CT)scan and enhanced CT scan obviously indicated RPF.Although this patient had a long course and renal insufficiency,we performed a kidney biopsy.Renal biopsy showed that the renal tubulointerstitium had focal plasma cell infiltration and increased lymphocyte infiltration accompanied by fibrosis.After combining the biopsy results with immunohistochemistry,it was found that the absolute number of positive IgG4+cells per high power field exceeded 10,and the ratio of IgG4/IgG was over 40%.Finally,the patient was diagnosed with IgG4-TIN complicated with RPF and given glucocorticoids as long-term maintenance therapy,helping him keep out of dialysis.After a follow-up of 19 mo,the patient had recovered well.Previous literature on IgG4-RKD and RPF was retrieved from PubMed to characterize the clinical and pathological features and to identify the diagnosis and treatment of IgG4-RKD.CONCLUSION Our case report demonstrates the clinical characteristics of IgG4-RKD complicated with RPF.Serum IgG4 is a favorable indicator for screening.Performing renal biopsy actively plays a vital role in diagnosis and treatment,even if the patient has a long course and manifests with renal insufficiency.It is remarkable to treat IgG4-RKD with glucocorticoids.Hence,early diagnosis and targeted therapy are essential for reversing renal function and improving extrarenal manifestations in patients with IgG4-RKD.
基金supported by the National High-Tech R&D Program(2014ZX09102042)the National Natural Science Foundation of China(81373142)the Natural Science Foundation of Yunnan Province(2012ZA009)
文摘Coxsackie virus A16(CA16) is commonly recognized as one of the main human pathogens of hand-foot-mouth disease(HFMD). The clinical manifestations of HFMD include vesicles of hand, foot and mouth in young children and severe inflammatory CNS lesions. In this study, experimentally CA16 infected tree shrews(Tupaia belangeri) were used to investigate CA16 pathogenesis. The results showed that both the body temperature and the percentages of blood neutrophilic granulocytes / monocytes of CA16 infected tree shrews increased at 4-7 days post infection. Dynamic distributions of CA16 in different tissues and stools were found at different infection stages. Moreover, the pathological changes in CNS and other organs were also observed. These findings indicate that tree shrews can be used as a viable animal model to study CA16 infection.
基金Supported by the National Natural Science Foundation of China,No.81174263National Science and Technology Major Project during the 12th Five-year Plan Period,No.2012ZX1005006+1 种基金Sanming Project of Medicine in Shenzhen,Guangdong Province,China,No.SZSM201612074and Science and Technology Planning Project of Guangdong Province,China,No.2017A020213016.
文摘BACKGROUND No guideline recommends antiviral therapy for hepatitis B e antigen(HBeAg)-positive chronic hepatitis B patients with persistently normal alanine aminotransferase levels and a high hepatitis B virus(HBV)DNA viral load.AIM To evaluate the feasibility and safety of a Chinese herbal formula as a therapeutic option for chronic HBV infection.METHODS In total,395 patients(30–65 years old)with confirmed HBeAg-positive chronic hepatitis B infection and persistently normal alanine aminotransferase were randomized to receive either Chinese herbal formula or placebo for 96 wk.Endpoints to evaluate therapeutic efficacy included:(1)HBV DNA levels decreased to less than 4 log10 IU/mL at weeks 48 and 96;and(2)HBeAg clearance and seroconversion rates at weeks 48 and 96.RESULTS HBV DNA levels≤4 log10 IU/mL were 10.05%at week 48 and 18.59%at week 96 in the treatment group.The HBeAg clearance and conversion rates were 8.54%and 8.04%at week 48 and 16.08%and 14.57%at week 96,respectively.However,HBV DNA levels≤4 log10 IU/mL were 2.55%and 2.55%at weeks 48 and 96,respectively,and the HBeAg clearance rates were 3.06%and 5.61%at weeks 48 and 96,respectively,in the control group.The quantitative hepatitis B surface antigen and HBeAg levels at baseline and changes during the treatment period as well as the alanine aminotransferase elevation at weeks 12 and 24 were strong predictors of HBeAg clearance.CONCLUSION High rates of HBV DNA reduction,HBeAg clearance and seroconversion could be achieved with Chinese herbal formula treatments,and the treatments were relatively safe for HBeAg-positive chronic hepatitis B-infected patients with persistently normal alanine aminotransferase.The ability of the compound to modulate host immune function probably contributed to this effect.
基金National Nature Science Founds(30670094 and 30560142)
文摘The Sindbis-like virus was first discovered in China in 1986. Its complete genomic sequence consists of more than 11 000 bp encoding more than 3 700 amino acids. It contains a 5' non-transcriptional region (5'-NTR) in a non-structural region, four non-structural proteins (nsP1, nsP2, nsP3, nsP4) regions, capsids in conserved and non-conserved regions and structural El, E2, E3, 6K regions and a 3' non-transcriptional region (3'-NTR). The Sindbis-IMB was isolated from the blood of a patient suspected to have encephalitis, and was followed by identification and passage. The virus RNA was extracted from virus supernatant in infected cells and the whole genome was divided into 12 fragments; RT-PCR was then performed to amplify the 12 fragments for complete sequencing. The results showed that the whole genomic sequence of Sindbis-IMB consists of 11 717 bp encoding 3 773 amino acids. Homology comparison with other Sindbis-like isolates demonstrated the highest similarity was the YN87448 with a variation of 1% strain isolated in Yunnan Province and the second highest to the SAAR86 strain with a variation of -1.2%. The nucleotide sequence variations were present in non-structural regions, resulting in amino acids K, E, N, R, H, and L in protein sequences in positions 230, 231,443,781, 1 582, and 1746 in the new isolation respectively. Furthermore, three additional amino acids-glutamic acid, serine and alanine-were noted in nsp4 terminus as compared to the YN87448 isolate
基金supported by the National Natural Science Foundation of China(Grant Nos.11803009 and 11603009)the Natural Science Foundation of Fujian Province(Grant Nos.2018J05006,2018J01416 and 2016J05013)。
文摘The form of timing residuals due to errors in pulsar spin period P and its derivative P, in positions, as well as in proper motions, has been well presented for decades in the literature. However,the residual patterns due to errors in the pulsar acceleration have not been reported previously, while a pulsar in the Galaxy or a globular cluster(GC) will be unavoidably accelerated. The coupling effect of the pulsar transverse acceleration and the R¨omer delay on timing residuals is simulated in this work. The results demonstrate that the residuals due to the effect can be identified by the oscillation envelopes of the residuals. It is also shown that the amplitude of the residuals due to the effect is usually relatively small,however, it may probably be observable for pulsars distributed in the vicinity of the core of a nearby GC.
文摘Meta-heuristics typically takes long time to search optimality from huge amounts of data samples for applications like communication, medicine, and civil engineering. Therefore, parallelizing meta-heuristics to massively reduce runtime is one hot topic in related research. In this paper, we propose a MapReduce modified cuckoo search (MRMCS), an efficient modified cuckoo search (MCS) implementation on a MapReduce architecture--Hadoop. MapReduce particle swarm optimization (MRPSO) from a previous work is also implemented for comparison. Four evaluation functions and two engineering design problems are used to conduct experiments. As a result, MRMCS shows better convergence in obtaining optimality than MRPSO with two to four times speed-up.
基金supported by the National Natural Science Foundation of China under Grant Nos.11803009 and 11603009the Natural Science Foundation of Fujian Province under Grant Nos.2018J05006,2018J01416 and 2016J05013。
文摘The acceleration of LMXB 4U 1820-30 derived from its orbital-period derivative P_(b)was supposed to be the evidence for an Intermediate-mass black hole(IMBH)in the Galactic globular cluster(GC)NGC 6624.However,we find that the anomalous P_(b)is mainly due to the gravitational wave emission,rather than the acceleration in cluster potential.Using the standard structure models of GCs,we simulate acceleration distributions for pulsars in the central region of the cluster.By fitting the acceleration of J1823-3021 A with the simulated distribution profiles(maximum values),it is suggested that an IMBH with mass M■950_(-350)^(+550)M_(⊙) may reside in the cluster center.We further show that the second period derivative P of J1823-3021 A is probably due to the gravitational perturbation of a nearby star.
基金the National Natural Science Foundation of China(Grant Nos.11803009 and 11603009)the Natural Science Foundation of Fujian Province(Grant Nos.2018J05006,2018J01416 and 2016J05013).
文摘We investigate pulsar timing residuals due to the coupling effect of the pulsar transverse acceleration and the Romer delay.The effect is relatively small and usually negligible.Only for pulsars in globular clusters,it is possibly important.The maximum residual amplitude,which is from the pulsar near the surface of the core of the cluster,is about tens of nanoseconds,and may hardly be identified for most globular clusters currently.However,an intermediate-mass black hole in the center of a cluster can apparently increase the timing residual magnitudes.Particularly for pulsars in the innermost core region,their residual magnitudes may be significant.The high-magnitude residuals,which are above critical lines of each cluster,are strong evidence for the presence of a black hole or dark remnants of comparable total mass in the center of the cluster.We also explored the timing effects of line-of-sight accelerations for the pulsars.The distribution of measured line-of-sight accelerations are simulated with a Monte Carlo method.Two-dimensional Kolmogorov-Smirnov tests are performed to reexamine the consistency of distributions of the simulated and reported data for various values of parameters of the clusters.It is shown that the structure parameters of Terzan 5 can be constrained well by comparing the distribution of measured lineof-sight accelerations with the distributions from Monte Carlo simulations.We find that the cluster has an upper limit on the central black hole/dark remnant mass of~6000 M⊙.
文摘Enterovirus 71 (EV71) can cause serious nervous system lesions but to date the pathogenesis has been unclear. Our results show that EV71 proliferates in the neural cells and leads to neural cell lesions. The study of the pathology of EV71 infection in neonatal rat brains shows that the invasive ability of EV71 to the nervous system in vivo may depend on many unknown factors.
文摘This paper considers the empirical Bayes (EB) estimation problem for the parameter β of the linear regression model y = Xβ+ ε with ε- N(0, σ^2I) given β. Based on Pitman closeness (PC) criterion and mean square error matrix (MSEM) criterion, we prove the superiority of the EB estimator over the ordinary least square estimator (OLSE).
基金Supported by the National Natural Science Foundation of China(No.11371051)
文摘In the system of m (m ≥ 2) seemingly unrelated regressions, we show that the Gauss-Markov estimator (GME) of any regression coefficients has unique simplified form, which exactly equals to the one- step covariance-adjusted estimator of the regression coefficients, and hence we conclude that for any finite k ≥ 2 the k-step covariance-adjusted estimator degenerates to the one-step covariance-adjusted estimator and the corresponding two-stage Aitken estimator has exactly one simplified form. Also, the unique simplified expression of the GME is just the estimator presented in the Theorem 1 of Wang' work [1988]. A new estimate of regression coefficients in seemingly unrelated regression system, Science in China, Series A 10, 1033-1040].
文摘Background Fournier’s gangrene(FG)is a rare life-threatening form of necrotizing fasciitis.The risk factors for septic shock in patients with FG are unclear.This study aimed to identify potential risk factors and develop a prediction model for septic shock in patients with FG.Methods This retrospective cohort study included patients who were treated for FG between May 2013 and May 2020 at the Sixth Affiliated Hospital,Sun Yat-sen University(Guangzhou,China).The patients were divided into a septic shock group and a non-septic shock group.An L1-penalized logistic regression model was used to detect the main effect of important factors and a penalized Quadratic Discriminant Analysis method was used to identify possible interaction effects between different factors.The selected main factors and interactions were used to obtain a logistic regression model based on the Bayesian information criterion.Results A total of 113 patients with FG were enrolled and allocated to the septic shock group(n=24)or non-septic shock group(n=89).The best model selected identified by backward logistic regression based on Bayesian information criterion selected temperature,platelets,total bilirubin(TBIL)level,and pneumatosis on pelvic computed tomography/magnetic resonance images as the main linear effect and Na^(+)×TBIL as the interaction effect.The area under the ROC curve of the probability of FG with septic shock by our model was 0.84(95%confidence interval,0.78–0.95).The Harrell’s concordance index for the nomogramwas 0.864(95%confidence interval,0.78–0.95).Conclusion We have developed a prediction model for evaluation of the risk of septic shock in patients with FG that could assist clinicians in identifying critically ill patients with FG and prevent them from reaching a crisis state.