AIM: To investigate the effects of long-term albumin administration on survival, recurrence of ascites and onset of other complications. METHODS: One hundred consecutive patients admitted for first-onset ascites wer...AIM: To investigate the effects of long-term albumin administration on survival, recurrence of ascites and onset of other complications. METHODS: One hundred consecutive patients admitted for first-onset ascites were randomized to receive diuretics plus human albumin 25 g/wk in the first year and 25 g every two wk thereafter (group 1) or diuretics alone (group 2). The primary endpoint was survival without liver transplantation. Secondary endpoints were recurrence of ascites and occurrence of other complications. RESULTS: Median follow-up was 84 (2-120) mo. Albu- min-treated patients had significantly greater cumulative survival rate (Breslow test= 7.05, P= 0.0078) and lower probability of ascites recurrence (51% versus 94%, P〈0.0001). Chronic albumin infusion resulted in a mean increase in survival of 16 mo. CONCLUSION: Long-term albumin administration after first-onset ascites significantly improves patients' survival and decreases the risk of ascites recurrence.展开更多
Purpose: Belt electrode skeletal muscle electrical stimulation (B-SES) can stimulate large portions of muscles including deep sites without localisation of the stimulation area. The purpose of this study is to investi...Purpose: Belt electrode skeletal muscle electrical stimulation (B-SES) can stimulate large portions of muscles including deep sites without localisation of the stimulation area. The purpose of this study is to investigate both immediate treatment effects of B-SES and long-term treatment effects of B-SES with passive exercise on range of motion (ROM) and muscle tone of lower extremities in bedridden elderly patients. Methods: Outcome measures before and after B-SES treatment alone (4 Hz, 20 min, both lower extremities) were examined for the immediate effect. Outcome measures were: ROM and Modified Ashworth scale (MAS) of hip flexion and adduction;knee flexion and extension;and knee joint distance at position of flexion abduction in hip (distance of knee). A randomized crossover trial was conducted to examine the long-term effect of adding B-SES to passive exercise on ROM and MAS. Results and Discussion: The immediate effect study had 18 patients. ROM and MAS of 4 joint angles in 2 joints and distance of knee significantly improved after B-SES treatment. The long-term effect study had 11 patients. Friedman test revealed ROM and MAS of 4 joint angles in 2 joints and distance of knee significantly improved during B-SES intervention but not control intervention. B-SES in addition to passive stretch has a more statistically significant effect on contracture and spasticity in large portions of the lower extremities of bedridden elderly patients than passive stretching alone. Conclusions: We consider B-SES a useful tool to improve the ROM in lower extremities of bedridden patients.展开更多
<span style="font-family:Verdana;">Bedridden patients remain in bed for various reasons, such as chronic illness, old age, and disability, and they cannot perform self-care activities completely or par...<span style="font-family:Verdana;">Bedridden patients remain in bed for various reasons, such as chronic illness, old age, and disability, and they cannot perform self-care activities completely or partially. The provision of care for bedridden patients is a major issue in the aging population. Effective rehabilitation is associated with several factors such as cooperation between the patient and the medical staff, selection of effective facilities, and the financial burden. The objective of this study was to evaluate the effect on the activities of daily living (ADL) of occlusion restoration using removable dentures in bedridden older people.</span><span> </span><span style="font-family:Verdana;">This case</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">control study comprised 32 bedridden older patients who were divided into two groups as follows: denture (n </span><span style="font-family:Verdana;">=</span><span style="font-family:Verdana;"> 18) and no-denture (n </span><span style="font-family:Verdana;">=</span><span style="font-family:Verdana;"> 14). No rehabilitation was provided to any of the patients. The patients were evaluated 3 months after placing the denture, and the ADLs were compared between the two groups. Of the 18 bedridden patients who received removable dentures, 55.6% demonstrated improvements in the ADLs, and the effects persisted for </span><span style="font-family:Verdana;">at least 3 months. No improvement in the ADL was observed in the no-denture</span><span style="font-family:Verdana;"> group.</span><span> </span><span style="font-family:Verdana;">The results of this study suggested that adequate occlusal support can improve the ADL of the elderly. Thus, it is important to take care of oral health early in life in order to maintain oral health, which could help prevent the decrease in the ADL during the later stages of life.</span>展开更多
Background: In the near future in Japan, chronic dialysis patients will likely face a situation where the aging and the lengthening of hemodialysis treatment periods will adversely affect the mobility-related activiti...Background: In the near future in Japan, chronic dialysis patients will likely face a situation where the aging and the lengthening of hemodialysis treatment periods will adversely affect the mobility-related activities of daily living (MR-ADL). The aim of this study was to investigate chronological change in MR-ADL among chronic dialysis patients in need of long-term care and the effect of admission to long-term care facilities on their MR-ADL. Methods: Data were analyzed from a long-term care eligibility assessment survey conducted in late March 2009 of 1000 individuals residing in Niigata City, Japan who were approved to receive long-term care. Then data from those individuals who had undergone the assessment survey ≥4 times over a period of ≥4 years were statistically evaluated. To reveal change in MR-ADL, this study performed a three-way analysis of variance with mean survey scores from assessment categories 2 - 5 containing questions related to MR-ADL as the independent variable and the number of eligibility assessment surveys (within-subjects factor), facility admission, and dialysis therapy (between-subjects factors) as dependent variables. Results: We observed the effect of facility admission in individuals aged >70 years for categories 2 - 5, and observed the effect of the number of assessment surveys taken only in women ≥80 years for categories 2 and 5. Regarding the effect of dialysis therapy, female dialysis patients aged ≥80 years and in need of long-term care scored significantly higher on survey items for transferring, grooming, toileting, eating, and instrumental activities of daily living, all of which are indicators of a moderate decline in ADL. Conclusions: Because dialysis is often initiated in women aged around 80 years, ADL in this group of individuals can be improved by the initiation and proper provision of dialysis.展开更多
Objective To explore quantitative electroencephalography in unconscious patients after severe traumatic brain injury (TBI) to predict awakening. Methods All cases were divided into two groups(the awake group 19 cases ...Objective To explore quantitative electroencephalography in unconscious patients after severe traumatic brain injury (TBI) to predict awakening. Methods All cases were divided into two groups(the awake group 19 cases and the unfavourable prognosis group 22 cases).Two weeks after admission the original EEGs were preformed in 41 patients suffering from severe TBI with duration of disturbance of展开更多
Objective To compare the effects of combined en bloc liver - pancreas transplantation ( LPT) with portal vein drainage and simultaneous combined kidney - pancreas transplantation ( KPT) with systemic venous drainage o...Objective To compare the effects of combined en bloc liver - pancreas transplantation ( LPT) with portal vein drainage and simultaneous combined kidney - pancreas transplantation ( KPT) with systemic venous drainage on the pancreatic endocrine function and related me-展开更多
OBJECTIVE:Admission hyperglycemia in acute myocardial infarction (MI) is related with increased in-hospital and long term mortality and major cardiac adverse events。 We aimed to investigate how admission hyperglycemi...OBJECTIVE:Admission hyperglycemia in acute myocardial infarction (MI) is related with increased in-hospital and long term mortality and major cardiac adverse events。 We aimed to investigate how admission hyperglycemia affects the short and long term outcomes in elderly patients >65 years) after primary percutaneous coronary intervention for ST elevation myocardial infarction。 METHODS:We retrospectively analyzed 677 consecutive elderly patients (mean age 72.2 ±5.4)。 Patients were divided into two groups according to admission blood glucose levels。 Group : low glucose group (LLG), glucose < 168 mg/dL; and Group 2: high glucose group (HGG), glucose >168 mg/dL。 RESULTS:In-hospital, long term mortality and in-hospital major adverse cardiac events were higher in the high admission blood glucose group (P <0.001)。 Multivariate regression analysis showed: Killip > 1, post-thrombolysis in MI <3 and admission blood glucose levels were independent predictors of in-hospital adverse cardiac events (P <0.001)。 CONCLUSIONS:Admission hyperglycemia in elderly patients presented with ST elevation myocardial infarction is an independent predictor of in-hospital major adverse cardiac events and is associated with in-hospital and long term mortality。展开更多
Objective · To compare the efficacy and prognostic factors of HCAG regimen with traditional IA regimen in the treatment of newly diagnosed elderly acute myeloid leukemia(AML) patients. Methods · Forty-one pa...Objective · To compare the efficacy and prognostic factors of HCAG regimen with traditional IA regimen in the treatment of newly diagnosed elderly acute myeloid leukemia(AML) patients. Methods · Forty-one patients with AML(aged 55-71 years) were randomly divided into two groups(Group HCAG and Group IA) between 2014 and 2016 for induction and consolidation therapy. Multivariate analysis was applied to identify prognostic factors for relapse-free survival(RFS). Results · A total of 29 patients(70.7%) achieved complete remission(CR). The estimated 2-year overall survival(OS) was 66.8% in Group HCAG and 75.4% in Group IA(P=0.913). The estimated 2-year RFS was 61.8% in Group HCAG and 49.1% in Group IA(P=0.411). Age remained as the unfavorable prognostic factor, leading to significant differences in OS and RFS. In addition, RFS was influenced by cytogenetic/molecular risk stratification. Conclusion · Although HCAG seemed not to particularly benefit the group, the dose reduction of anthracyclines may be applied in elderly patients with comparable short-time outcome. Furthermore, the introduction of homoharringtonine resulted in an improvement of treatment response for more than 20% compared with CAG regimen.展开更多
Background: Single port laparoscopic cholecystectomy (SPLC) is a widely performed advanced technique in laparoscopic surgery which has many benefits compare to conventional three port laparoscopic cholecystectomy (TPL...Background: Single port laparoscopic cholecystectomy (SPLC) is a widely performed advanced technique in laparoscopic surgery which has many benefits compare to conventional three port laparoscopic cholecystectomy (TPLC). The purpose of this study was to compare the patients’ satisfaction of SPLC and TPLC after one year of operation by using questionnaire which not only objective factors such as results of operation and hospital days but also subjective factor such as social and cosmetic quality of life. Materials and Methods: This study analyzed the data of 74 patients (SPLC = 42, TPLC = 32) who underwent the laparoscopic cholecystectomy between March and July 2013. The patients were asked to complete a patient-assessment questionnaire measuring the postoperative social and cosmetic quality-of-life values at the 12-month mark. Results: Statistically significant differences in the age, sex distribution, and body mass index are absent between the two groups. All the average scores of the different parameters of the social-activity aspect—satisfaction with physical condition, limitation of nutrition, stamina, postoperative pain level, returning to social life, impairment of social life, degree of complications, and cost-effectiveness of the surgery—are not statistically significant in both groups. Alternatively, all the results of the cosmetic aspect—scar influence on charms (p p = 0.015), and patient’s score of scars (p < 0.001)—show statistically significant differences. Conclusion: The SPLC is a safe and an attractive approach regarding the patients of this study. It offers a more effective cosmetic result that may be conveyed by a greater patient satisfaction.展开更多
Objective:To systematic evaluation by the dorsalis pedis artery puncture for bed patients blood gas analysis of application effect of impact.Methods:A randomized controlled trial of the effect of arterial blood extrac...Objective:To systematic evaluation by the dorsalis pedis artery puncture for bed patients blood gas analysis of application effect of impact.Methods:A randomized controlled trial of the effect of arterial blood extraction on blood gas analysis in PubMed,CNKI,Wanfang database and VIP database.After selecting the literature,extracting the data and evaluating the quality of the literature.Meta- analysis was carried out by RevMan 5.3 software.Results:Twelve randomized controlled trials were included and 1696 patients were enrolled.After meta-analysis,the arterial puncture can effectively improve the success of arterial puncture in patients with bed [Z = 5.78,95%CI(1.90,3.66),P<0.001],reduce the occurrence of hematoma [Z = 4.27,95%CI(0.19,0.54),P<0.001],reduce the mistaken into the vein [Z = 4.60,95%CI(0.08,0.36),P<0.001],reduce cyanosis [Z = 2.84,95%CI(0.23,0.81),P<0.008],the difference was statistically significant.Conclusion:Dorsalis pedis artery puncture can improve the success rate of blood gas analysis in bedridden patients,reduce the incidence of hematoma and the incidence of venous leakage,and can be widely used in clinical practice.展开更多
A society of advanced age is arriving with the increasing number of elderly patients. Little attention has been paid to the quality of life of elderly patients, which is decreasing gradually. This article aims to stud...A society of advanced age is arriving with the increasing number of elderly patients. Little attention has been paid to the quality of life of elderly patients, which is decreasing gradually. This article aims to study the quality of life among elderly patients and explore the factors influencing it, in addition to exploring effective ways to improve the quality of life of elderly patients.展开更多
In the clinical practice of orthopedics,geriatric patients are prone to form and exhibit complex and diverse clinical complications during long-term bedridden treatment.This can result in poor survival rate and advers...In the clinical practice of orthopedics,geriatric patients are prone to form and exhibit complex and diverse clinical complications during long-term bedridden treatment.This can result in poor survival rate and adverse final clinical outcomes.Hence,it is essential to select appropriate methods for nursing intervention and health-care support for long-term bedridden geriatric orthopedic patients.It is of great significance to support and guarantee patients to obtain the best clinical results.This article focuses on the topic of interventional health effects of traditional Chinese medicine negative-heeled shoes in orthopedic bedridden patients,and two specific aspects were selected for a brief explanation.展开更多
基金Supported by grants from the Italian Ministry of Education, University and Research and the University of Florence, Italy
文摘AIM: To investigate the effects of long-term albumin administration on survival, recurrence of ascites and onset of other complications. METHODS: One hundred consecutive patients admitted for first-onset ascites were randomized to receive diuretics plus human albumin 25 g/wk in the first year and 25 g every two wk thereafter (group 1) or diuretics alone (group 2). The primary endpoint was survival without liver transplantation. Secondary endpoints were recurrence of ascites and occurrence of other complications. RESULTS: Median follow-up was 84 (2-120) mo. Albu- min-treated patients had significantly greater cumulative survival rate (Breslow test= 7.05, P= 0.0078) and lower probability of ascites recurrence (51% versus 94%, P〈0.0001). Chronic albumin infusion resulted in a mean increase in survival of 16 mo. CONCLUSION: Long-term albumin administration after first-onset ascites significantly improves patients' survival and decreases the risk of ascites recurrence.
文摘Purpose: Belt electrode skeletal muscle electrical stimulation (B-SES) can stimulate large portions of muscles including deep sites without localisation of the stimulation area. The purpose of this study is to investigate both immediate treatment effects of B-SES and long-term treatment effects of B-SES with passive exercise on range of motion (ROM) and muscle tone of lower extremities in bedridden elderly patients. Methods: Outcome measures before and after B-SES treatment alone (4 Hz, 20 min, both lower extremities) were examined for the immediate effect. Outcome measures were: ROM and Modified Ashworth scale (MAS) of hip flexion and adduction;knee flexion and extension;and knee joint distance at position of flexion abduction in hip (distance of knee). A randomized crossover trial was conducted to examine the long-term effect of adding B-SES to passive exercise on ROM and MAS. Results and Discussion: The immediate effect study had 18 patients. ROM and MAS of 4 joint angles in 2 joints and distance of knee significantly improved after B-SES treatment. The long-term effect study had 11 patients. Friedman test revealed ROM and MAS of 4 joint angles in 2 joints and distance of knee significantly improved during B-SES intervention but not control intervention. B-SES in addition to passive stretch has a more statistically significant effect on contracture and spasticity in large portions of the lower extremities of bedridden elderly patients than passive stretching alone. Conclusions: We consider B-SES a useful tool to improve the ROM in lower extremities of bedridden patients.
文摘<span style="font-family:Verdana;">Bedridden patients remain in bed for various reasons, such as chronic illness, old age, and disability, and they cannot perform self-care activities completely or partially. The provision of care for bedridden patients is a major issue in the aging population. Effective rehabilitation is associated with several factors such as cooperation between the patient and the medical staff, selection of effective facilities, and the financial burden. The objective of this study was to evaluate the effect on the activities of daily living (ADL) of occlusion restoration using removable dentures in bedridden older people.</span><span> </span><span style="font-family:Verdana;">This case</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">control study comprised 32 bedridden older patients who were divided into two groups as follows: denture (n </span><span style="font-family:Verdana;">=</span><span style="font-family:Verdana;"> 18) and no-denture (n </span><span style="font-family:Verdana;">=</span><span style="font-family:Verdana;"> 14). No rehabilitation was provided to any of the patients. The patients were evaluated 3 months after placing the denture, and the ADLs were compared between the two groups. Of the 18 bedridden patients who received removable dentures, 55.6% demonstrated improvements in the ADLs, and the effects persisted for </span><span style="font-family:Verdana;">at least 3 months. No improvement in the ADL was observed in the no-denture</span><span style="font-family:Verdana;"> group.</span><span> </span><span style="font-family:Verdana;">The results of this study suggested that adequate occlusal support can improve the ADL of the elderly. Thus, it is important to take care of oral health early in life in order to maintain oral health, which could help prevent the decrease in the ADL during the later stages of life.</span>
文摘Background: In the near future in Japan, chronic dialysis patients will likely face a situation where the aging and the lengthening of hemodialysis treatment periods will adversely affect the mobility-related activities of daily living (MR-ADL). The aim of this study was to investigate chronological change in MR-ADL among chronic dialysis patients in need of long-term care and the effect of admission to long-term care facilities on their MR-ADL. Methods: Data were analyzed from a long-term care eligibility assessment survey conducted in late March 2009 of 1000 individuals residing in Niigata City, Japan who were approved to receive long-term care. Then data from those individuals who had undergone the assessment survey ≥4 times over a period of ≥4 years were statistically evaluated. To reveal change in MR-ADL, this study performed a three-way analysis of variance with mean survey scores from assessment categories 2 - 5 containing questions related to MR-ADL as the independent variable and the number of eligibility assessment surveys (within-subjects factor), facility admission, and dialysis therapy (between-subjects factors) as dependent variables. Results: We observed the effect of facility admission in individuals aged >70 years for categories 2 - 5, and observed the effect of the number of assessment surveys taken only in women ≥80 years for categories 2 and 5. Regarding the effect of dialysis therapy, female dialysis patients aged ≥80 years and in need of long-term care scored significantly higher on survey items for transferring, grooming, toileting, eating, and instrumental activities of daily living, all of which are indicators of a moderate decline in ADL. Conclusions: Because dialysis is often initiated in women aged around 80 years, ADL in this group of individuals can be improved by the initiation and proper provision of dialysis.
文摘Objective To explore quantitative electroencephalography in unconscious patients after severe traumatic brain injury (TBI) to predict awakening. Methods All cases were divided into two groups(the awake group 19 cases and the unfavourable prognosis group 22 cases).Two weeks after admission the original EEGs were preformed in 41 patients suffering from severe TBI with duration of disturbance of
文摘Objective To compare the effects of combined en bloc liver - pancreas transplantation ( LPT) with portal vein drainage and simultaneous combined kidney - pancreas transplantation ( KPT) with systemic venous drainage on the pancreatic endocrine function and related me-
文摘OBJECTIVE:Admission hyperglycemia in acute myocardial infarction (MI) is related with increased in-hospital and long term mortality and major cardiac adverse events。 We aimed to investigate how admission hyperglycemia affects the short and long term outcomes in elderly patients >65 years) after primary percutaneous coronary intervention for ST elevation myocardial infarction。 METHODS:We retrospectively analyzed 677 consecutive elderly patients (mean age 72.2 ±5.4)。 Patients were divided into two groups according to admission blood glucose levels。 Group : low glucose group (LLG), glucose < 168 mg/dL; and Group 2: high glucose group (HGG), glucose >168 mg/dL。 RESULTS:In-hospital, long term mortality and in-hospital major adverse cardiac events were higher in the high admission blood glucose group (P <0.001)。 Multivariate regression analysis showed: Killip > 1, post-thrombolysis in MI <3 and admission blood glucose levels were independent predictors of in-hospital adverse cardiac events (P <0.001)。 CONCLUSIONS:Admission hyperglycemia in elderly patients presented with ST elevation myocardial infarction is an independent predictor of in-hospital major adverse cardiac events and is associated with in-hospital and long term mortality。
基金National Natural Science Foundation of China(81270621,81300451)National Public Health Grand Research Foundation(201202003)+1 种基金Shanghai Health System Advanced and Appropriate Technology Promotion Projects(2013SY001)Multiple Clinical Research Center Program of Shanghai Jiao Tong University School of Medicine(DLY201513)
文摘Objective · To compare the efficacy and prognostic factors of HCAG regimen with traditional IA regimen in the treatment of newly diagnosed elderly acute myeloid leukemia(AML) patients. Methods · Forty-one patients with AML(aged 55-71 years) were randomly divided into two groups(Group HCAG and Group IA) between 2014 and 2016 for induction and consolidation therapy. Multivariate analysis was applied to identify prognostic factors for relapse-free survival(RFS). Results · A total of 29 patients(70.7%) achieved complete remission(CR). The estimated 2-year overall survival(OS) was 66.8% in Group HCAG and 75.4% in Group IA(P=0.913). The estimated 2-year RFS was 61.8% in Group HCAG and 49.1% in Group IA(P=0.411). Age remained as the unfavorable prognostic factor, leading to significant differences in OS and RFS. In addition, RFS was influenced by cytogenetic/molecular risk stratification. Conclusion · Although HCAG seemed not to particularly benefit the group, the dose reduction of anthracyclines may be applied in elderly patients with comparable short-time outcome. Furthermore, the introduction of homoharringtonine resulted in an improvement of treatment response for more than 20% compared with CAG regimen.
文摘Background: Single port laparoscopic cholecystectomy (SPLC) is a widely performed advanced technique in laparoscopic surgery which has many benefits compare to conventional three port laparoscopic cholecystectomy (TPLC). The purpose of this study was to compare the patients’ satisfaction of SPLC and TPLC after one year of operation by using questionnaire which not only objective factors such as results of operation and hospital days but also subjective factor such as social and cosmetic quality of life. Materials and Methods: This study analyzed the data of 74 patients (SPLC = 42, TPLC = 32) who underwent the laparoscopic cholecystectomy between March and July 2013. The patients were asked to complete a patient-assessment questionnaire measuring the postoperative social and cosmetic quality-of-life values at the 12-month mark. Results: Statistically significant differences in the age, sex distribution, and body mass index are absent between the two groups. All the average scores of the different parameters of the social-activity aspect—satisfaction with physical condition, limitation of nutrition, stamina, postoperative pain level, returning to social life, impairment of social life, degree of complications, and cost-effectiveness of the surgery—are not statistically significant in both groups. Alternatively, all the results of the cosmetic aspect—scar influence on charms (p p = 0.015), and patient’s score of scars (p < 0.001)—show statistically significant differences. Conclusion: The SPLC is a safe and an attractive approach regarding the patients of this study. It offers a more effective cosmetic result that may be conveyed by a greater patient satisfaction.
文摘Objective:To systematic evaluation by the dorsalis pedis artery puncture for bed patients blood gas analysis of application effect of impact.Methods:A randomized controlled trial of the effect of arterial blood extraction on blood gas analysis in PubMed,CNKI,Wanfang database and VIP database.After selecting the literature,extracting the data and evaluating the quality of the literature.Meta- analysis was carried out by RevMan 5.3 software.Results:Twelve randomized controlled trials were included and 1696 patients were enrolled.After meta-analysis,the arterial puncture can effectively improve the success of arterial puncture in patients with bed [Z = 5.78,95%CI(1.90,3.66),P<0.001],reduce the occurrence of hematoma [Z = 4.27,95%CI(0.19,0.54),P<0.001],reduce the mistaken into the vein [Z = 4.60,95%CI(0.08,0.36),P<0.001],reduce cyanosis [Z = 2.84,95%CI(0.23,0.81),P<0.008],the difference was statistically significant.Conclusion:Dorsalis pedis artery puncture can improve the success rate of blood gas analysis in bedridden patients,reduce the incidence of hematoma and the incidence of venous leakage,and can be widely used in clinical practice.
文摘A society of advanced age is arriving with the increasing number of elderly patients. Little attention has been paid to the quality of life of elderly patients, which is decreasing gradually. This article aims to study the quality of life among elderly patients and explore the factors influencing it, in addition to exploring effective ways to improve the quality of life of elderly patients.
文摘In the clinical practice of orthopedics,geriatric patients are prone to form and exhibit complex and diverse clinical complications during long-term bedridden treatment.This can result in poor survival rate and adverse final clinical outcomes.Hence,it is essential to select appropriate methods for nursing intervention and health-care support for long-term bedridden geriatric orthopedic patients.It is of great significance to support and guarantee patients to obtain the best clinical results.This article focuses on the topic of interventional health effects of traditional Chinese medicine negative-heeled shoes in orthopedic bedridden patients,and two specific aspects were selected for a brief explanation.