Brain-computer interface(BCI)technology is rapidly advancing in medical research and application.As an emerging biomedical engineering technology,it has garnered significant attention in the clinical research of brain...Brain-computer interface(BCI)technology is rapidly advancing in medical research and application.As an emerging biomedical engineering technology,it has garnered significant attention in the clinical research of brain disease diagnosis and treatment,neurological rehabilitation,and mental health.However,BCI also raises several challenges and ethical concerns in clinical research.In this article,the authors investigate and discuss three aspects of BCI in medicine and healthcare:the state of international ethical governance,multidimensional ethical challenges pertaining to BCI in clinical research,and suggestive concerns for ethical review.Despite the great potential of frontier BCI research and development in the field of medical care,the ethical challenges induced by itself and the complexities of clinical research and brain function have put forward new special fields for ethics in BCI.To ensure"responsible innovation"in BCI research in healthcare and medicine,the creation of an ethical global governance framework and system,along with special guidelines for cutting-edge BCI research in medicine,is suggested.展开更多
BACKGROUND Diabetes foot is one of the most serious complications of diabetes and an important cause of death and disability,traditional treatment has poor efficacy and there is an urgent need to develop a practical t...BACKGROUND Diabetes foot is one of the most serious complications of diabetes and an important cause of death and disability,traditional treatment has poor efficacy and there is an urgent need to develop a practical treatment method.AIM To investigate whether Huangma Ding or autologous platelet-rich gel(APG)treatment would benefit diabetic lower extremity arterial disease(LEAD)patients with foot ulcers.METHODS A total of 155 diabetic LEAD patients with foot ulcers were enrolled and divided into three groups:Group A(62 patients;basal treatment),Group B(38 patients;basal treatment and APG),and Group C(55 patients;basal treatment and Huangma Ding).All patients underwent routine follow-up visits for six months.After follow-up,we calculated the changes in all variables from baseline and determined the differences between groups and the relationships between parameters.RESULTS The infection status of the three groups before treatment was the same.Procalcitonin(PCT)improved after APG and Huangma Ding treatment more than after traditional treatment and was significantly greater in Group C than in Group B.Logistic regression analysis revealed that PCT was positively correlated with total amputation,primary amputation,and minor amputation rates.The ankle-brachial pressure and the transcutaneous oxygen pressure in Groups B and C were greater than those in Group A.The major amputation rate,minor amputation rate,and total amputation times in Groups B and C were lower than those in Group A.CONCLUSION Our research indicated that diabetic foot ulcers(DFUs)lead to major amputation,minor amputation,and total amputation through local infection and poor microcirculation and macrocirculation.Huangma Ding and APG were effective attreating DFUs.The clinical efficacy of Huangma Ding was better than that of autologous platelet gel,which may be related to the better control of local infection by Huangma Ding.This finding suggested that in patients with DFUs combined with coinfection,controlling infection is as important as improving circulation.展开更多
BACKGROUNDIn the post-pandemic era, the emergence of sporadic cases of coronavirus disease 2019 (COVID-19) and the scale of the pandemic are unpredictable. Therefore, the impact ofsporadic cases of COVID-19 and isolat...BACKGROUNDIn the post-pandemic era, the emergence of sporadic cases of coronavirus disease 2019 (COVID-19) and the scale of the pandemic are unpredictable. Therefore, the impact ofsporadic cases of COVID-19 and isolation measures on mental health and sleep in different groupsof people need to be analyzed.AIMTo clarify the severity of psychological problems and insomnia of staff and community residentsaround a hospital with sporadic cases of COVID-19, and their relationship with quarantinelocation and long-term changes.METHODSA cross-sectional survey was conducted on community residents and medical staff. Many of thesemedical staff had been subjected to different places of quarantine. Community residents did notexperience quarantine. Hospital anxiety and depression scale (HADS), acute stress disorder scale(ASDS) and insomnia severity index (ISI) were used to evaluate anxiety and depression, acutestress disorder symptoms, and the severity of insomnia. Additionally, we conducted a 1-yearfollow-up study on medical staff, with related scales measurement immediately after and one yearafter the 2-wk quarantine period.RESULTSWe included 406 medical staff and 226 community residents. The total scores of ISI and subscale inHADS of community residents were significantly higher than that of medical staff. Furtheranalysis of medical staff who experienced quarantine showed that 134 were quarantined in hotels,70 in hospitals and 48 at home. Among all subjects, the proportions of HADS, ASDS and ISI scoresabove normal cutoff value were 51.94%, 19.17% and 31.11%, respectively. Multivariable logisticregression analysis found that subjects with higher total ASDS scores had a greater risk to developanxiety and depression. The total ISI score for medical staff in hotel quarantine was significantlyhigher than those in home quarantine. Total 199 doctors and nurses who completed the 1-yearfollow-up study. Compared with baseline, HADS and ASDS scores decreased significantly oneyear after the end of quarantine, while ISI scores did not change significantly.CONCLUSIONSporadic COVID-19 cases had a greater psychological impact on residents in surroundingcommunities, mainly manifested as insomnia and depressive symptoms. Hotel quarantineaggravated the severity of insomnia in medical staff, whose symptoms lasted ≥ 1 year.展开更多
Abstract A new microfluidic system with four different microchambers (a circle and three equilateral concave polygons) was designed and fabricated using poly(dimethylsiloxane) (PDMS) and the soft lithography met...Abstract A new microfluidic system with four different microchambers (a circle and three equilateral concave polygons) was designed and fabricated using poly(dimethylsiloxane) (PDMS) and the soft lithography method. Using this microfluidic device at six flow rates (5, 10, 20, 30, 40, and 50 μL/h), the effects of microenvironmental geometry and aqueous flow on bacterial adhesion behaviors were investigated. Escherichia coli HB101 pGLO, which could produce a green fluorescent protein induced by L-arabinose, was utilized as the model bacteria. The results demonstrated that bacterial adhesion was significantly related to culture time, microenvironment geometry, and aqueous flow rates. Adhered bacterial density increased with the culture time. Initially, the adhesion occurred at the microchamber sides, and then the entire chamber was gradually covered with increased culture time. Adhesion densities in the side zones were larger than those in the center zones because of the lower shearing force in the side zone. Also, the adhesion densities in the complex chambers were larger than those in the simple chambers. At low flow rates, the orientation of adhered bacteria was random and disorderly. At high flow rates, bacterial orientation became close to the streamline and oriented toward the flow direction; All these results implied that bacterial adhesion tended to occur in complicated aqueous flow areas.The present study provided an on-chip flow system for physiological behavior of biological cells, as well as provided a strategic cue for the prevention of bacterial infection and biofilm formation.展开更多
Objective To clarify the role of mast cells and neuropeptides substance P (SP), somatostatin (SS), and vasoactive intestinal peptide (VIP) in dextran sulfate sodium (DSS)-induced colitis in rats. Methods Expe...Objective To clarify the role of mast cells and neuropeptides substance P (SP), somatostatin (SS), and vasoactive intestinal peptide (VIP) in dextran sulfate sodium (DSS)-induced colitis in rats. Methods Experimental colitis was induced in Sprague-Dawley rats (180-200 g, n=20) by oral in- gestion of 4% (w/v) DSS in drinking water for 7 days. Control rats (n=5) drank water and were sacrificed on day 0. Mast cell number, histamine levels in whole blood and tissue, tissue levels of SP, SS and, VIP in the dis- tal colon of the rats were measured on day 8, day 13, and day 18 of experimentation. Results Oral administration of 4% DSS solution for 7 days resulted in surface epithelial loss and crypt loss in the distal colon. Mast cell count increased on day 8 (1.75±1.09/mm vs. 0.38±0.24/mm, P〈0.05) and day 13 (1.55±1.01/mm vs. 0.38±0.24/mm, P〈0.05) after DSS treatment. Whole blood his- tamine levels were increased on day 8 (266.93±35.62 ng/mL vs. 76.87±32.28 ng/mL, P〈0.01) and gradu- ally decreased by clay 13 and day 18 after DSS treatment. Histamine levels in the distal colon were decreased on day 8 (1.77±0.65 ng/mg vs. 3.06±0.87 ng/mg, P〈0.05) and recovered to control levels by day 13 after DSS treatment. SP level in the distal colon gradually increased and were raised significantly by day 13 (8777.14±3056.14 pg/mL vs. 4739.66±3299.81 pg/mL, P〈0.05) after DSS treatment. SS and VIP levels in the distal colon were not changed. Conclusions Mast cell degranulation followed by histamine release may play an important role in the pathogenesis of colitis induced by DSS. SP may be a significant substance in the progression of inflamma- tion and the recovery process of DSS-induced colitis.展开更多
Objective: To analyze reflux parameters by means of combined multichannel intraluminal impedance and pH (MII-pH) monitoring in patients with gastroesophageal reflux disease (GERD) symptoms off medication, and to ...Objective: To analyze reflux parameters by means of combined multichannel intraluminal impedance and pH (MII-pH) monitoring in patients with gastroesophageal reflux disease (GERD) symptoms off medication, and to find the reflux characteristics of Chinese GERD patients and the influences of gender, age, body posture, and body mass index (BMI) on gastroesophageal reflux (GER). Methods: Between Dec. 2008 and May 2014, 125 patients with typical GERD symptoms were subjected to 24-h MII-pH monitoring. Twelve patients with normal MII-pH profiles were not considered for analysis. The reflux parameters of 113 GERD patients with abnormal Mll-pH results were analyzed. Results: (1) DeMeester scores were above the normal range in 46.90% (53/113) of GERD patients. Weakly acidic refluxes were prevalent in GERD patients, and the frequency of abnormal weakly acidic reflux was 75.22% (85/113). The frequencies of abnormal symptom index (SI) and symptom association probability (SAP) were 19.47% (22/113) and 14.16% (16/113), respectively. (2) The frequencies of DeMeester scores, the %time at pH〈4, and the numbers of reflux episodes and of long reflux episodes 〉5 min were significantly higher in male patients than in female patients. (3) The %time at pH〈4 was much higher during upright periods than during supine periods. During supine periods, 31.86% (36/113) of GERD patients had delayed bolus clearance time, compared with 19.47% (22/113) during upright periods. (4) The number of abnormal DeMeester scores, %time at pH〈4, and the number of acid refluxes during upright periods were significantly higher in obese GERD patients than in GERD patients with a normal BMI. Over- weight GERD patients also had many more acid refluxes during upright periods than GERD patients with a normal BMI Conclusions: Weakly acidic refluxes were prevalent in Chinese GERD patients. The factors male, gender, upright position, obesity (BMI〉25), but not age, may increase the frequency and severity of GER.展开更多
Objective:To determine the characteristics of postprandial proximal gastric acid pockets(PPGAPs)and their association with gastroesophageal acid reflux in patients with Barrett’s esophagus(BE).Methods:Fifteen patient...Objective:To determine the characteristics of postprandial proximal gastric acid pockets(PPGAPs)and their association with gastroesophageal acid reflux in patients with Barrett’s esophagus(BE).Methods:Fifteen patients with BE(defined by columnar lined esophagus of≥1 cm)and 15 healthy individuals that were matched for age,gender,and body mass index,were recruited.The fasting intragastric p H and the appearance time,length,lowest p H,and mean p H of the PPGAP were determined using a single p H electrode pull-through experiment.For BE patients,a gastroesophageal reflux disease questionnaire(Gerd Q)was completed and esophageal 24-h p H monitoring was carried out.Results:The PPGAP was significantly longer(5(3,5)cm vs.2(1,2)cm)and the lowest p H(1.1(0.8,1.5)vs.1.6(1.4,1.9))was significantly lower in patients with short-segment BE than in healthy individuals.The PPGAP started to appear proximally from the gastroesophageal p H step-up point to the esophageal lumen.The acidity of the PPGAP was higher in the distal segment than in the proximal segment.In short-segment BE patients,there were significant correlations between the acidity and the appearance time and length of the PPGAP.The length and acidity of the PPGAP were positively associated with gastroesophageal acid reflux episodes.The acidity of the PPGAP was associated with the De Meester scores,the Gerd Q scores,and the fasting intragastric p H.Conclusions:In patients with short-segment BE,a PPGAP is commonly seen.Its length and acidity of PPGAP are associated with gastroesophageal acid reflux,the De Meester score,and the Gerd Q score in patients with short-segment BE.展开更多
This paper deals with an initial boundary value problem for a class of nonlinear wave equation with nonlinear damping and source terms whose solution may blow up in finite time.An explicit lower bound for blow up time...This paper deals with an initial boundary value problem for a class of nonlinear wave equation with nonlinear damping and source terms whose solution may blow up in finite time.An explicit lower bound for blow up time is determined by means of a differential inequality argument if blow up occurs.展开更多
基金supported by the Ministry of Science and Tech-nology of the People's Republic of China(2021ZD0201900),Project 5(2021ZD0201905).
文摘Brain-computer interface(BCI)technology is rapidly advancing in medical research and application.As an emerging biomedical engineering technology,it has garnered significant attention in the clinical research of brain disease diagnosis and treatment,neurological rehabilitation,and mental health.However,BCI also raises several challenges and ethical concerns in clinical research.In this article,the authors investigate and discuss three aspects of BCI in medicine and healthcare:the state of international ethical governance,multidimensional ethical challenges pertaining to BCI in clinical research,and suggestive concerns for ethical review.Despite the great potential of frontier BCI research and development in the field of medical care,the ethical challenges induced by itself and the complexities of clinical research and brain function have put forward new special fields for ethics in BCI.To ensure"responsible innovation"in BCI research in healthcare and medicine,the creation of an ethical global governance framework and system,along with special guidelines for cutting-edge BCI research in medicine,is suggested.
基金Supported by the Chongqing Science and Technology Bureau and Health Commission of Chinese Medicine Technology Innovation and Application Development Project,No.2020ZY013540General Project of Chongqing Natural Science Foundation,No.CSTB2023NSCQMSX0246 and No.CSTB2022NSCQ-MSX1271Science and Health Joint Project of Dazu District Science and Technology Bureau,No.DZKJ2022JSYJ1001.
文摘BACKGROUND Diabetes foot is one of the most serious complications of diabetes and an important cause of death and disability,traditional treatment has poor efficacy and there is an urgent need to develop a practical treatment method.AIM To investigate whether Huangma Ding or autologous platelet-rich gel(APG)treatment would benefit diabetic lower extremity arterial disease(LEAD)patients with foot ulcers.METHODS A total of 155 diabetic LEAD patients with foot ulcers were enrolled and divided into three groups:Group A(62 patients;basal treatment),Group B(38 patients;basal treatment and APG),and Group C(55 patients;basal treatment and Huangma Ding).All patients underwent routine follow-up visits for six months.After follow-up,we calculated the changes in all variables from baseline and determined the differences between groups and the relationships between parameters.RESULTS The infection status of the three groups before treatment was the same.Procalcitonin(PCT)improved after APG and Huangma Ding treatment more than after traditional treatment and was significantly greater in Group C than in Group B.Logistic regression analysis revealed that PCT was positively correlated with total amputation,primary amputation,and minor amputation rates.The ankle-brachial pressure and the transcutaneous oxygen pressure in Groups B and C were greater than those in Group A.The major amputation rate,minor amputation rate,and total amputation times in Groups B and C were lower than those in Group A.CONCLUSION Our research indicated that diabetic foot ulcers(DFUs)lead to major amputation,minor amputation,and total amputation through local infection and poor microcirculation and macrocirculation.Huangma Ding and APG were effective attreating DFUs.The clinical efficacy of Huangma Ding was better than that of autologous platelet gel,which may be related to the better control of local infection by Huangma Ding.This finding suggested that in patients with DFUs combined with coinfection,controlling infection is as important as improving circulation.
基金Supported by the Beijing Municipal Science&Technology Commission,No. Z191107006619091National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital),No. NCRC2020M07National Natural Science Foundation of China,No. 81871071
文摘BACKGROUNDIn the post-pandemic era, the emergence of sporadic cases of coronavirus disease 2019 (COVID-19) and the scale of the pandemic are unpredictable. Therefore, the impact ofsporadic cases of COVID-19 and isolation measures on mental health and sleep in different groupsof people need to be analyzed.AIMTo clarify the severity of psychological problems and insomnia of staff and community residentsaround a hospital with sporadic cases of COVID-19, and their relationship with quarantinelocation and long-term changes.METHODSA cross-sectional survey was conducted on community residents and medical staff. Many of thesemedical staff had been subjected to different places of quarantine. Community residents did notexperience quarantine. Hospital anxiety and depression scale (HADS), acute stress disorder scale(ASDS) and insomnia severity index (ISI) were used to evaluate anxiety and depression, acutestress disorder symptoms, and the severity of insomnia. Additionally, we conducted a 1-yearfollow-up study on medical staff, with related scales measurement immediately after and one yearafter the 2-wk quarantine period.RESULTSWe included 406 medical staff and 226 community residents. The total scores of ISI and subscale inHADS of community residents were significantly higher than that of medical staff. Furtheranalysis of medical staff who experienced quarantine showed that 134 were quarantined in hotels,70 in hospitals and 48 at home. Among all subjects, the proportions of HADS, ASDS and ISI scoresabove normal cutoff value were 51.94%, 19.17% and 31.11%, respectively. Multivariable logisticregression analysis found that subjects with higher total ASDS scores had a greater risk to developanxiety and depression. The total ISI score for medical staff in hotel quarantine was significantlyhigher than those in home quarantine. Total 199 doctors and nurses who completed the 1-yearfollow-up study. Compared with baseline, HADS and ASDS scores decreased significantly oneyear after the end of quarantine, while ISI scores did not change significantly.CONCLUSIONSporadic COVID-19 cases had a greater psychological impact on residents in surroundingcommunities, mainly manifested as insomnia and depressive symptoms. Hotel quarantineaggravated the severity of insomnia in medical staff, whose symptoms lasted ≥ 1 year.
基金supported by the National Natural Science Foundation of China (Nos.20975082 and 20775059)the Ministry of Education of the People’s Republic of China (NCET-08-0464),the Scientific Research Foundation for Returned Overseas Chinese Scholars,by the State Education Ministry,by the Northwest A&F University
文摘Abstract A new microfluidic system with four different microchambers (a circle and three equilateral concave polygons) was designed and fabricated using poly(dimethylsiloxane) (PDMS) and the soft lithography method. Using this microfluidic device at six flow rates (5, 10, 20, 30, 40, and 50 μL/h), the effects of microenvironmental geometry and aqueous flow on bacterial adhesion behaviors were investigated. Escherichia coli HB101 pGLO, which could produce a green fluorescent protein induced by L-arabinose, was utilized as the model bacteria. The results demonstrated that bacterial adhesion was significantly related to culture time, microenvironment geometry, and aqueous flow rates. Adhered bacterial density increased with the culture time. Initially, the adhesion occurred at the microchamber sides, and then the entire chamber was gradually covered with increased culture time. Adhesion densities in the side zones were larger than those in the center zones because of the lower shearing force in the side zone. Also, the adhesion densities in the complex chambers were larger than those in the simple chambers. At low flow rates, the orientation of adhered bacteria was random and disorderly. At high flow rates, bacterial orientation became close to the streamline and oriented toward the flow direction; All these results implied that bacterial adhesion tended to occur in complicated aqueous flow areas.The present study provided an on-chip flow system for physiological behavior of biological cells, as well as provided a strategic cue for the prevention of bacterial infection and biofilm formation.
基金Supported by Scientific and Technological Project of Shaanxi Province (2004K13G1)
文摘Objective To clarify the role of mast cells and neuropeptides substance P (SP), somatostatin (SS), and vasoactive intestinal peptide (VIP) in dextran sulfate sodium (DSS)-induced colitis in rats. Methods Experimental colitis was induced in Sprague-Dawley rats (180-200 g, n=20) by oral in- gestion of 4% (w/v) DSS in drinking water for 7 days. Control rats (n=5) drank water and were sacrificed on day 0. Mast cell number, histamine levels in whole blood and tissue, tissue levels of SP, SS and, VIP in the dis- tal colon of the rats were measured on day 8, day 13, and day 18 of experimentation. Results Oral administration of 4% DSS solution for 7 days resulted in surface epithelial loss and crypt loss in the distal colon. Mast cell count increased on day 8 (1.75±1.09/mm vs. 0.38±0.24/mm, P〈0.05) and day 13 (1.55±1.01/mm vs. 0.38±0.24/mm, P〈0.05) after DSS treatment. Whole blood his- tamine levels were increased on day 8 (266.93±35.62 ng/mL vs. 76.87±32.28 ng/mL, P〈0.01) and gradu- ally decreased by clay 13 and day 18 after DSS treatment. Histamine levels in the distal colon were decreased on day 8 (1.77±0.65 ng/mg vs. 3.06±0.87 ng/mg, P〈0.05) and recovered to control levels by day 13 after DSS treatment. SP level in the distal colon gradually increased and were raised significantly by day 13 (8777.14±3056.14 pg/mL vs. 4739.66±3299.81 pg/mL, P〈0.05) after DSS treatment. SS and VIP levels in the distal colon were not changed. Conclusions Mast cell degranulation followed by histamine release may play an important role in the pathogenesis of colitis induced by DSS. SP may be a significant substance in the progression of inflamma- tion and the recovery process of DSS-induced colitis.
文摘Objective: To analyze reflux parameters by means of combined multichannel intraluminal impedance and pH (MII-pH) monitoring in patients with gastroesophageal reflux disease (GERD) symptoms off medication, and to find the reflux characteristics of Chinese GERD patients and the influences of gender, age, body posture, and body mass index (BMI) on gastroesophageal reflux (GER). Methods: Between Dec. 2008 and May 2014, 125 patients with typical GERD symptoms were subjected to 24-h MII-pH monitoring. Twelve patients with normal MII-pH profiles were not considered for analysis. The reflux parameters of 113 GERD patients with abnormal Mll-pH results were analyzed. Results: (1) DeMeester scores were above the normal range in 46.90% (53/113) of GERD patients. Weakly acidic refluxes were prevalent in GERD patients, and the frequency of abnormal weakly acidic reflux was 75.22% (85/113). The frequencies of abnormal symptom index (SI) and symptom association probability (SAP) were 19.47% (22/113) and 14.16% (16/113), respectively. (2) The frequencies of DeMeester scores, the %time at pH〈4, and the numbers of reflux episodes and of long reflux episodes 〉5 min were significantly higher in male patients than in female patients. (3) The %time at pH〈4 was much higher during upright periods than during supine periods. During supine periods, 31.86% (36/113) of GERD patients had delayed bolus clearance time, compared with 19.47% (22/113) during upright periods. (4) The number of abnormal DeMeester scores, %time at pH〈4, and the number of acid refluxes during upright periods were significantly higher in obese GERD patients than in GERD patients with a normal BMI. Over- weight GERD patients also had many more acid refluxes during upright periods than GERD patients with a normal BMI Conclusions: Weakly acidic refluxes were prevalent in Chinese GERD patients. The factors male, gender, upright position, obesity (BMI〉25), but not age, may increase the frequency and severity of GER.
基金Project supported by the Natural Science Foundation of Inner Mongolia Autonomous Region(Nos.2019LH08042 and 2018MS08050)the Natural Science Foundation of Baotou Medical College(No.BYJJ-YF-2018024),China。
文摘Objective:To determine the characteristics of postprandial proximal gastric acid pockets(PPGAPs)and their association with gastroesophageal acid reflux in patients with Barrett’s esophagus(BE).Methods:Fifteen patients with BE(defined by columnar lined esophagus of≥1 cm)and 15 healthy individuals that were matched for age,gender,and body mass index,were recruited.The fasting intragastric p H and the appearance time,length,lowest p H,and mean p H of the PPGAP were determined using a single p H electrode pull-through experiment.For BE patients,a gastroesophageal reflux disease questionnaire(Gerd Q)was completed and esophageal 24-h p H monitoring was carried out.Results:The PPGAP was significantly longer(5(3,5)cm vs.2(1,2)cm)and the lowest p H(1.1(0.8,1.5)vs.1.6(1.4,1.9))was significantly lower in patients with short-segment BE than in healthy individuals.The PPGAP started to appear proximally from the gastroesophageal p H step-up point to the esophageal lumen.The acidity of the PPGAP was higher in the distal segment than in the proximal segment.In short-segment BE patients,there were significant correlations between the acidity and the appearance time and length of the PPGAP.The length and acidity of the PPGAP were positively associated with gastroesophageal acid reflux episodes.The acidity of the PPGAP was associated with the De Meester scores,the Gerd Q scores,and the fasting intragastric p H.Conclusions:In patients with short-segment BE,a PPGAP is commonly seen.Its length and acidity of PPGAP are associated with gastroesophageal acid reflux,the De Meester score,and the Gerd Q score in patients with short-segment BE.
基金supported by big data and Educational Statistics Application Laboratory(2017WSYS001)Guangdong University of Finance and Economics。
文摘This paper deals with an initial boundary value problem for a class of nonlinear wave equation with nonlinear damping and source terms whose solution may blow up in finite time.An explicit lower bound for blow up time is determined by means of a differential inequality argument if blow up occurs.