[A clinical study of high dependency units to reduce ICU readmission rates in patients with severe liver disease].

Objective: To investigate the real-world difference in the ICU readmission rate between the high-dependency unit (HDU) and the general ward so as to reflect the role of HDU in the diagnosis and management of patients with SLD. Methods: Patients with severe liver disease who were consecutively enrolled were step-downed to HDU and general wards in the ICU of the Fifth Medical Center of the People's Liberation Army General Hospital between July 2017 and December 2021. The main liver function indicators, MELD scores, and other were compared between the two groups. SLD severity, ICU readmission rates, and others differences were analyzed among the patients transferred to different wards. The HDU role was clarified for SLD patients' grade management. The area under the curve of the receiver operating characteristic curve (AUROC) was used to calculate and explore the feasibility of a baseline Model for End-Stage Liver Disease (MELD) score to define the treatment scope of HDU. Results: The SLD group of patients who were transferred to HDU had significantly higher levels of the international normalized ratio, bilirubin, alanine aminotransferase, MELD score, and other factors compared to those in the general ward (P < 0.05). 70.7% of SLD patients in the HDU group had a MELD score > 17, while 61.9% of SLD patients in the general ward group had a MELD score ≤ 17. The overall ICU readmission rate in this cohort was 11.4%. The ICU readmission rate was significantly higher with a MELD score of > 23 (20.0%) than that with a MELD score of ≤ 23 (8.6%) in patients with SLD, according to the MELD score quartile P75 (P = 0.020). The ICU readmission rate was 8.2% when MELD score ≤ 23, and 9.1% when MELD score>23 in the HDU group, with no statistically significant difference (P = 1.000). However, in the general ward group, the ICU readmission rate in patients with a MELD score ≤ 23 was 8.8%, and when the MELD score was >23, the ICU readmission rate significantly increased to 36.4% (P = 0.001). The optimal cut-off value of the MELD score for predicting ICU readmission in patients with SLD in the general ward group was 23.5. Conclusion: The high-dependency unit can better undertake ICU step-down patients with SLD and significantly reduce the ICU readmission rate with MELD scores > 23 in practice. Additionally, ICU step-down SLD patients with a MELD score > 23 are suitable for transfer to HDU treatment.

[Analysis of the clinical predictive value of lactate on the prognosis of patients with acute-on-chronic liver failure combined with infection].

Objective: To explore the predictive value of lactic acid for the adverse prognostic outcomes in patients with acute-on-chronic liver failure combined with infection. Methods: A retrospective analysis was conducted on the clinical data of 208 cases of ACLF combined with infection who were hospitalized from January 2014 to March 2016. Patients were divided into a survival group (n = 83) and a mortality group (n = 125) according to the results of a 90-day follow-up. The clinical data were statistically analyzed between the two groups. Multivariate logistic regression with two categorical variables was used to analyze the independent risk factors for 90-day disease mortality and establish a new prediction model. The receiver operating characteristic curve (ROC curve) was used to evaluate the predictive value of lactic acid, the MELD score, the MELD-Na score, lactic acid combined with the MELD score, lactic acid combined with the MELD-Na score, and the new model. Results: The 90-day mortality rate of 208 cases of ACLF combined with infection was 60.1%. There were statistically significant differences in white blood cell count, neutrophil count, total bilirubin (TBil), serum creatinine (Cr), blood urea nitrogen (BUN), blood ammonia, the international normalized ratio (INR), lactic acid (LAC), procalcitonin, the MELD score, the MELD-Na score, hepatic encephalopathy (HE), acute kidney injury (AKI), and bleeding between the two groups. Multivariate logistic regression analysis showed that TBil, INR, LAC, HE, and bleeding were independent risk factors for 90-day mortality in patients with ACLF combined with infection. After the establishment of MELD-LAC, MELD-Na-LAC, and a new prediction model, the ROC curve revealed that the AUC (95% confidence interval) of MELD-LAC and MELD-Na LAC were 0.819 (0.759 ~ 0.870) and 0.838 (0.780 ~ 0.886), respectively, and was superior than the MELD score [0.766 (0.702 ~ 0.823)] and MELD-Na score [0.788 (0.726 ~ 0.843)], with P < 0.05, while the new model had an AUC of 0.924, the sensitivity of 83.9%, specificity of 89.9%, and accuracy of 87.8%, which was higher than LAC, MELD score, MELD-Na score, MELD-LAC, and MELD-Na-LAC (P < 0.01). Conclusion: Lactic acid is an independent risk factor for mortality in patients with ACLF combined with infection, and it improves the clinical predictive value of MELD and MELD-Na for the prognosis of mortality.

[An epigenetic clock model for assessing the human biological age of healthy aging].

Objective: To construct an epigenetic clock model for assessing and calibrating human biological age. Methods: Convenience sampling was used to select 186 subjects from the longevity cohort of Guangxi Zhuang Antonornous Region from July 1 to November 30, 2019, and 124 subjects from the physical examination population of the Seventh Medical Center of the PLA General Hospital from October 1 to December 31, 2020. Self-designed questionnaire was applied to collect demographic characteristics and family history of disease. Physical examination was applied to determine heart rate and blood pressure. Fasting peripheral venous blood was drawn for determination of fasting plasma glucose, plasma total cholesterol, triglyceride, plasma high-density lipoprotein cholesterol, plasma low-density lipoprotein cholesterol and telomere length. Methylation levels of EDARADD cg09809672, IPO8 cg19722847, NHLRC1 cg22736354, P2RX6 cg05442902 and SCGN cg06493994 were detected by targeted methylation site sequencing. A total of 54 subjects with unqualified quality control of DNA methylation and telomere length were excluded, and 256 subjects' data were finally analyzed. Trend test was used for the change of methylation level among different ages groups, multiple linear regression method was used to build prediction models of biological age. Kendal rank correlation analysis was used to evaluate the correlation of age gap (Gregorian calendar age minus biological age) with telomere length. Independent sample t-test was used to compare the health-related indicators between subjects with different age gap within different age groups. Results: The M(Q1, Q3)of age of subjects were 67 (51, 91) years old, including 166 females (64.84%). With increase of age, the methylation levels of gene loci were decreased (EDARADD cg09809672, IPO8 cg19722847 and P2RX6 cg05442902) and increased (NHLRC1 cg22736354 and SCGN cg06493994) (all P values<0.05). The established biological age prediction model was as follows: Y=-53.121×EDARADD cg09809672-137.564×IPO8 cg19722847+141.040×NHLRC1 cg22736354-67.893×P2RX6 cg05442902+149.547×SCGNcg06493994+4.592×sex+64.185 (R2=0.86, P<0.001), where Y was the biological age, and the items in the equation were methylation level, sex (male =1, female =2) and intercept in sequence. The Kendall rank correlation coefficient between age gap and telomere length was 0.731 (P<0.001). Compared with the subjects whose age gaP<0, the subjects with age gaP≥0 had higher systolic blood pressure in adolescence [(88.50±8.89) and (109.83±9.48) mmHg, respectively, 1 mmHg=0.133 kPa]; lower TC [(5.48±0.23) and (3.98±0.54) mmol/L, respectively, ] and TG [(3.51±0.32) and (3.41±0.20) mmol/L] in young adults; lower fasting blood glucose in middle age [(6.17±0.67) and (5.37±0.79) mmol/L, respectively, ] and higher diastolic blood pressure in nonagenarian age [(76.99±6.78) and (83.97±9.36) mmHg, respectively, ] (all P values<0.05). Conclusion: The constructed epigenetic clock model can be used to evaluate and calibrate human biological age.

[The study on the distribution characteristics and relevant factors of healthy and long-lived people in multiple regions of Guangxi Zhuang Autonomous Region].

Objective: To investigate the epidemiological characteristics and relevant factors among individuals characterized by their longevity in multiple regions of Guangxi Zhuang Autonomous Region, and provide a valuable scientific perspective for the research in health and longevity of the elderly in Guangxi. Methods: Registration and face-to-face questionnaire on a door-to-door basis were adopted to collect the demographic characteristics of the long-lived individuals (≥90 years old) in Bama of Hechi city, Yongfu of Guilin city, Dongxing of Fangchenggang city, Guangxi. Then, among the local general population, individuals within the age group between 40 and 85 years old were selected randomly as controls. Correlations were then analyzed between the relative health and longevity of the subjects and their gender, ethnicity, family history, disease history, marital status, the number of family generations, the number of children, smoking, drinking, outdoor activities, sleep and other health-related factors, then the result was subject to further analysis by comparing the long-lived population and the control population respectively. Results: Among 691 500 of the permanent residents of Bama, Yongfu and Dongxing city, 1 005 cases were 90 years old and over with a ratio of 145.34 out of 100 000 persons; within the 1 005 cases, 944 were aged between 90 and 100 (longevity rate: 136.51/100 000) with an average age of (93.28±2.57); 61 cases were aged 100 or over, arriving at a centenarian rate of 8.82/100 000 with an average age of (102.00±3.05) years. Significant differences were found just among three particular factors - regional distribution (P=0.014), history of disease (P=0.002), four generations of family (P=0.008) between nonagenarians and centenarians (P<0.05), while the other 15 indicators did not show anything noteworthy. The result indicated that longevity and centenarians might be the same group and then we combined both groups into one. By cross-comparison between the longevity-plus- centenarians and the control group in the region, factors listed below exhibited significant correlation with health and longevity: marital status (OR=26.469, 95%CI: 13.208-53.045), number of generations within the family (OR=5.419, 95%CI: 3.418-8.592), number of male offspring (OR=2.013, 95%CI: 1.555-2.607), number of female offspring (OR=1.380, 95%CI: 1.122-1.696), and the frequency of outdoor activities (OR=10.226, 95%CI: 3.164-33.045). Conclusions: The longevity rate is higher in the general natural population in Bama, Yongfu and Dongxing of Guangxi. The phenomenon may owe to favorable family structure, atmosphere within or out of the family or other elements related with social surrounding. Among them all, mentality, inclination to physical exercise and regular rhythm of life may all exert tremendous contributory influence here.

[Analysis of distribution characteristics and influencing factors of healthy and long-lived people in Shanglin area of Nanning, Guangxi Zhuang Autonomous Region].

Objective: To explore the epidemiologic characteristics of long-lived population and influencing factors in Shanglin county of Guangxi and provide scientific basis for the study of health and longevity in Guangxi. Methods: We collected and analyzed the general demographic cross-sectional data of the long-lived individuals (≥90 years old) in 11 villages and towns by multi-source registration and face-to-face interview. The age group control design was adopted to conduct a comparison among the longevity group (90-100 years old), centenarian group (≥100 years old), the longevity plus centenarian group and control group (local population aged 40-85 years), and identify the factors related to longevity. Results: Among the 496 007 people registered in Shanglin, 1 533 were aged ≥90 years, including 1 453 in the longevity group, with an average age of (92.84±2.46) years, and 80 in the centenarian group, with an average age of (102.67±2.60) years. The spatial distribution of long-lived individuals and centenarians was mainly in the north and central areas, and sparse in southwest area. Analysis on factors related to health and longevity indicated that old people with Zhuang ethnic (OR=1.551,95%CI:1.308-1.838), married (OR=55.507,95%CI:36.087-85.377) and moderately high waist-to-hip ratio (OR=258.056,95%CI:27.775-2 397.569), and SBP (OR=1.019,95%CI:1.013-1.026) tended to live longer. Conclusions: We found that the rate of longevity in Shanglin was higher than the average level in Guangxi and China. Longevity in Shanglin country had unique spatial and population distribution characterics of female longevity more than male longevity, mainly Zhuang ethnic and so on. Being women, married, family history of longevity, appropriate high waist-to-hip ratio, SBP and blood sugar level might be positive factors for longevity in Shanglin, but the impacts of other factors on longevity need further study.

[Clinical characteristics of infection-induced acute renal injury in acute-on-chronic liver failure].

Objective: To investigate the incidence rate, influencing factors and prognosis of infection-induced acute renal injury (AKI) in patients with acute-on-chronic liver failure (ACLF). Methods: 516 cases with acute-on-chronic liver failure complicated with infection that were hospitalized in our hospital during 2014 to 2016 were retrospectively studied. General conditions and clinical characteristics of the patients were collected, and grouped according to the presence or absence of incidence and severity of AKI. General conditions, laboratory results, occurrence of complications and survival were compared and analyzed. Results: The main causes were HBV infection (67.8%) and alcoholic liver disease (20.0%). The most common sites of infection were abdominal cavity, lung and blood. Multivariate analysis showed that neutrophil count, TBIL, lactate and septic shock were independent risk factors for infection-induced AKI in ACLF patients. The cumulative mortality in patients with AKI after infection at 28, 90 and 360 days was significantly higher than those without AKI (51.6% and 20.5%, 70.2% and 40.3%, 73.4% and 45.9%; P < 0.01). In both groups, deaths had occurred mainly in the early (0 ~ 28 d) and middle (29 ~ 90 d) stage of follow-up period. In the late follow-up period (91-360 d), there was no statistically significant difference in mortality rate between the two groups. Conclusion: Infection is an important inducing cause of AKI in ACLF patients. The underlying liver disease and the severity of infection are significantly related to the infection-induced AKI in ACLF patients, and once AKI occurs after infection, the mortality rate of the patients is significantly increased.

[Visual-spatial and temporal characteristics related to infectious Tuberculosis epidemics in Guangxi Zhuang Autonomous Region, 2012-2015].

Objective: To study the spatial and temporal mode of infectious TB transmission in Guangxi Zhuang Autonomous Region (Guangxi). Methods: Data related to infectious TB case (Include smear and/or culture positive patients) in Guangxi were collected from the National Notifiable Disease Reported System (NNDRS) from 2010 to 2015. Spatial-temporal analysis and prediction were performed by SaTScan 7.0.2, GeoDa 1.8.12, R program v 3.3.1 and SPSS 19.0 software, using the time series model, Moran's I global and local spatial autocorrelation (Empirical Bayes adjustment). Kulldorff 's space-time scan statistics displayed by R software was used to identify the temporal and spatial trend of TB. Results: The total number of infectious TB cases, collected from NNDRS was 76 151, and showing a decreasing trend on annual incidence (value of Chi-square for Linear trend=3 464.53, P-value=0.000). The forecast value of TB cases in 2016 was 7 764 (4 971-10 557), with peak in March, analyzed through the Winters'multiplicative model. The Moran's I global Statistics was greater than 0 (0.257-0.390). TB cluster seemed to have been existed for several years. The most significant hot spots seemed to be mainly located in the central and western parts of Guangxi, shown by local spatial autocorrelation statistics and the result from space-time scanning.Counties or districts that located in the east parts of Guangxi presented the low-low relation (significant cold spots). The situation of infectious TB seemed migratory. Conclusions: Our data showed an annual decreasing trend of incidence on infectious TB with temporal concentration in spring and summer. Main clusters (hot spots) were found to be located in the central and western parts of Guangxi. Hopefully, our findings can provide clues to uncover the real mode of TB transmission at the molecular-biological level.

[Application of percutaneous AngioJet thrombectomy in patients with acute symptomatic portal and superior mesenteric venous thrombosis].

Objective: To evaluate the clinical value of percutaneous AngioJet thrombectomy in treatment of acute symptomatic portal and superior mesenteric venous thrombosis venous thrombosis (PVMVT) . Method: From January 2014 to January 2016, a total of 8 patients in Nanjing First Hospital with PVMVT verified by color Doppler ultrasound and computed tomographic angiography (CTA) were analyzed retrospectively. Under ultrasound guidance , the branch of the right portal vein(PV) was punctured with a micropuncture set and a 4-F infusion catheter was advanced to the superior mesenteric vein(SMV). The venogram demonstrated the thrombosis in the PV/SMV and a 6-F AngioJet Xpeeedior catheter was advanced over the guidewire and positioned in the distal SMV. Percutaneous thrombectomy was performed after a mixture of 250 000 U of urokinase in 100 ml of normal saline for mechanical pulse spray of thrombus in all patients for approximately 15 minutes. 2 patients underwent PTA and stent implantation after the thrombectomy procedure, 1 of them and the others 6 patients received continuous transcatheter infusion of urokinase (500 000 U/d) for 24 or 48 hours until the thrombosis was completely dissolved confirmed by angiography at 24 and 48 hours.After procedure and the thrombolytic therapy was discontinued, removal of the infusion catheter and the sheath from the liver, the transhepatic tract was embolized with coils or gelfoam to reduce the risk of bleeding. The patency rate of PV /SMV was assessed by CTA at 1 and 6 months after the procedure. Patients were discharged with oral anticoagulation regimen for at least 6 months.The following criteria were used in evaluation of thrombolysis: grade Ⅰ<50% thrombus removal; grade Ⅱ 50%~90% thrombus removal, and grade Ⅲ>90% thrombus removal. Results: All 8 patients with PVMVT were treated by AngioJet thrombectomy. Angiography after the thrombectomy procedure showed complete thrombus removal (>90%) was in 3 cases, substantial thrombus removal (50%~90%) in 5 cases. Grade Ⅲ (complete) thrombolysis was achieved in 7 cases and grade Ⅱ (50%~90%) lysis in 1 case post thrombolytic therapy for 24 or 48 hours. 2 patients had underwent PTA and stent implantation. Large volume intraperitoneal hemorrhage was discovered in 1 patient after removal of the catheter and sheath from the liver. The patient restored stability after a blood transfusion.Venous patency was comfirmed in all 8 patients at 1 or 6 months after the treatment. There was no patient with major complications death related to the procedure. Conclusion: Percutaneous AngioJet thrombectomy with adjunctive thrombolytic therapy is an effective and safe treatment modality in patients with acute symptomatic PVMVT.

[Efficacy comparison of interventional treatment by anterograde or retrograde catheterization for acute lower extremity deep venous thrombosis].

Objective: To compare the clinical efficacy differences between anterograde and retrograde catheterization interventional treatment for acute low extremity deep venous thrombosis(DVT). Methods: The clinical data of 217 patients with acute low extremity DVT between January 2009 and December 2014 were analyzed retrospectively. Group A: 67 patients underwent treated with anterograde catheterization interventional treatment. Group B: 150 patients underwent treated with retrograde catheterization interventional treatment. The degree of thrombolysis in different anatomical sites, clinical effective rate, femoral-popliteal vein valve reflux and the incidence of post-thrombotic syndrome(PTS) were all analyzed. Results: There were no statistical differences in the degree of thrombolysis (≥50%) of common iliac vein, external iliac vein and common femoral vein between group A (83.6%, 88.1%, 91.0%)and B (80.7%, 82.0%, 88.0%)(all P>0.05). The degree of thrombolysis (≥50%) of superficial femoral vein in group A(94.0%) was significantly higher than that of group B (75.3%)(P=0.001). There was no significantly difference in the clinical effective rate at discharged between group A (80.6%) and B(76.7%)( P=0.519). During follow-up of 44±15 months, There was no statistical difference in the patency rate of the iliofemoral vein, the valvular regurgitation of patent femoropopliteal vein and the incidence of PTS between group A(70.2%, 25.4%, 35.8%) and B (60.0%, 31.5%, 40.0%)(all P>0.05). The incidence of PTS in patients with iliofemoral vein patency(13.1%) was significantly lower than that in patients with iliofemoral vein occlusion (82.5%)(P<0.01). Conclusions: The anterograde or retrograde catheterization interventional treatment can be used for treating acute low extremity DVT and get comparable clinical effect.The retrograde catheterization does not increase venous valve damage. The recovery of iliofemoral vein lumen patency is the main task in the treatment of DVT and can significantly reduce the incidence of PTS.

The anesthetic agent sevoflurane attenuates pulmonary acute lung injury by modulating apoptotic pathways.

The objective of this study was to evaluate lung protection by the volatile anesthetic sevoflurane (SEVO), which inhibits apoptosis. Male Sprague-Dawley rats (250-280 g; n=18) were randomly divided into three groups. The LPS group received 5 mg/kg endotoxin (lipopolysaccharide), which induced acute lung injury (ALI). The control (CTRL) group received normal saline and the SEVO group received sevoflurane (2.5%) for 30 min after ALI was induced by 5 mg/kg LPS. Samples were collected for analysis 12 h after LPS. Lung injury was assessed by pathological observations and tissue wet to dry weight (W/D) ratios. Apoptotic index (AI) was determined by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay and electron microscopy. Caspase-3 and cleaved-caspase-3 protein levels were determined by immunocytochemistry and western blotting, respectively. Bcl-xl levels were measured by western blotting and Bcl-2 levels by quantitative real-time polymerase chain reaction and western blotting. In the LPS group, W/D ratios, AI values, caspase-3 and cleaved-caspase-3 levels were significantly higher than in the CTRL group and lung injury was more severe. In the SEVO group, W/D ratios, AI, caspase-3 and cleaved-caspase-3 were lower than in the LPS group. Bcl-2 and Bcl-xl expression were higher than in the LPS group and lung injury was attenuated. Sevoflurane inhalation protected the lungs from injury by regulating caspase-3 activation and Bcl-xl and Bcl-2 expression to inhibit excessive cell apoptosis, and such apoptosis might be important in the pathogenesis of LPS-induced ALI.

Phase Transformations in the High-Tc Superconducting Compounds, Ba2RCu3O7-δ (R = Nd, Sm, Gd, Y, Ho, and Er).

The phase transformation between the orthorhombic and tetragonal structures of six high-T c superconductors, Ba2RCu3O7- δ , where R = Nd, Sm, Gd, Y, Ho, and Er, and δ = 0 to 1, has been investigated using techniques of x-ray diffraction, differential thermal analysis/thermogravimetric analysis (DTA/TGA) and electron diffraction. The transformation from the oxygen-rich orthorhombic phase to the oxygen-deficient tetragonal phase involves two orthorhombic phases. A superlattice cell caused by oxygen ordering, with a' = 2a, was observed for materials with smaller ionic radius (Y, Ho, and Er). For the larger lanthanide samples (Nd, Sm, and Gd), the a' = 2a type superlattice cell was not observed. The structural phase transition temperatures, oxygen stoichiometry and characteristics of the T c plateaus appear to correlate with the ionic radius, which varies based on the number of f electrons. Lanthanide elements with a smaller ionic radius stabilize the orthorhombic phase to higher temperatures and lower oxygen content. Also, the superconducting temperature is less sensitive to the oxygen content for materials with smaller ionic radius. The trend of dependence of the phase transformation temperature on ionic radius across the lanthanide series can be explained using a quasi-chemical approximation (QCA) whereby the strain effect plays an important role on the order-disorder transition due to the effect of oxygen content on the CuO chain sites.

Respiratory carbon losses and the carbon-use efficiency of a northern hardwood forest, 1999-2003.

Quantitative assessment of carbon (C) storage by forests requires an understanding of climatic controls over respiratory C loss. Ecosystem respiration can be estimated biometrically as the sum (R Sigma) of soil (Rs), leaf (Rl) and wood (Rw) respiration, and meteorologically by measuring above-canopy nocturnal CO2 fluxes (Fcn). Here we estimated R Sigma over 5 yr in a forest in Michigan, USA, and compared R Sigma and Fcn on turbulent nights. We also evaluated forest carbon-use efficiency (Ec = P(NP)/P(GP)) using biometric estimates of net primary production (P(NP)) and R Sigma and Fcn-derived estimates of gross primary production (P(GP)). Interannual variation in R Sigma was modest (142 g C m(-2) yr(-1)). Mean annual R Sigma was 1425 g C m(-2) yr(-1); 71% from Rs, 18% from Rl, and 11% from Rw. Hourly R Sigma was well correlated with Fcn, but 11 to 58% greater depending on the time of year. Greater R Sigma compared with Fcn resulted in higher estimated annual P(GP) and lower annual Ec (0.42 vs 0.54) using biometric and meteorological data, respectively. Our results provide one of the first multiyear estimates of R Sigma in a forested ecosystem, and document the responses of component respiratory C losses to major climatic drivers. They also provide the first assessment of Ec in a deciduous forest using independent estimates of P(GP).

Environmental controls on sap flow in a northern hardwood forest.

Our objective was to gain a detailed understanding of how photosynthetically active radiation (PAR), vapor pressure deficit (D) and soil water interact to control transpiration in the dominant canopy species of a mixed hardwood forest in northern Lower Michigan. An improved understanding of how these environmental factors affect whole-tree water use in unmanaged ecosystems is necessary in assessing the consequences of climate change on the terrestrial water cycle. We used continuously heated sap flow sensors to measure transpiration in mature trees of four species during two successive drought events. The measurements were scaled to the stand level for comparison with eddy covariance estimates of ecosystem water flux (Fw). Photosynthetically active radiation and D together explained 82% of the daytime hourly variation in plot-level transpiration, and low soil water content generally resulted in increased stomatal sensitivity to increasing D. There were also species-specific responses to drought. Quercus rubra L. showed low water use during both dry and wet conditions, and during periods of high D. Among the study species, Acer rubrum L. showed the greatest degree of stomatal closure in response to low soil water availability. Moderate increases in stomatal sensitivity to D during dry periods were observed in Populus grandidentata Michx. and Betula papyrifera Marsh. Sap flow scaled to the plot level and Fw demonstrated similar temporal patterns of water loss suggesting that the mechanisms controlling sap flow of an individual tree also control ecosystem evapotranspiration. However, the absolute magnitude of scaled sap flow estimates was consistently lower than Fw. We conclude that species-specific responses to PAR, D and soil water content are key elements to understanding current and future water fluxes in this ecosystem.

[Research of cryosurgery in the treatment of maxillo-facial deepish hemangioma].

OBJECTIVE: To observe the effect of cryosurgery on maxillofacial deepish hemangioma, and the facial nerve recovery. METHODS: Twelve hemangioma patients were observed for the effect of cryosurgery on hemangiomaa in maxillo-facial deepish expose lesion after flapping and four rabbits were used for the observation of the recovery of the facial nerve after cryosurgery. RESULTS: The facial nerve function of rabbits recovered within six to eight weeks, the twelve hemangioma patients'-facial nerve also recovered with six to eight weeks, only one reoccured in five years. CONCLUSIONS: Cryosurgery after flapping is an effective; little-traumatic, recover-quickly and spreadingworth method for treatment of maxillo-facial deepish hemangioma.

[Facial nerve dysfunction after various surgical managements for benign parotid tumor].

OBJECTIVE: To observe the incidence of facial nerve dysfunction following parotidectomy and the relationship of the extent of parotid gland resection and the histopathology types. METHODS: Clinical observation of 99 patients who underwent parotid surgery from 1996 to 2000 was studied to analyse the relation between facial nerve dysfunction and the extent of parotidectomy with House-Backmann grading system. RESULTS: The overall incidence of facial dysfunction (HB > 1) was 36.4% for temporary and 3% for permanent dysfunction; Most of the dysfunction were partial and most concerning the marginal mandibular branch (34/99). The temporary facial dysfunction rate in total parotidectomy is higher than that of superficial and local parotidectomy. CONCLUSION: The dysfunction of facial nerve branches is correlated with the surgical managements. The most facial never dysfunction is temporary. The size of the lesion and the histopathology types will influence the choice of surgical managements. A proper surgical managements would reduce the incidence of facial dysfunction.

Shortening and superlon-wrapping the downstream tube can increase the useful range of the blood warmer.

BACKGROUND: Hypothermia occurs frequently in clinical anesthesia. Many apparatus were introduced to keep intravenous fluid warm. But at low to medium flow rates little effects have been achieved because of heat lost along the tube. Superlon, an industrial heat-preserving material widely used in air conditioning to prevent temperature change, has never been used in the blood warmer. METHODS: The study was performed in three groups group I using standard (120 cm) unwrapped tube (Animac AM-4 set), group II using a shortened downstream tube (60 cm), and group III using the downstream tube which was further wrapped with superlon (Super LTD). The blood warmer used was identical in all 3 groups. We recorded the fluid temperatures at different points downstream at various flow rates. The values were then compared among groups. RESULTS: The fluid temperatures before entering the warmer were around 20 degrees C and 37 degrees C at the 2 cm post-warmer points at various flow rates. The end point temperatures rose with flow rates and were the highest in group III and lowest in group I at each flow rate (p < 0.01). In group III the temperature could be kept above 32 degrees C at a very low flow rate (150 ml/h) and above 35 degrees C at 300 ml/h. In group I, 1,000 to 2,000 ml/h were needed to keep the same temperature. CONCLUSIONS: These refinements increase the useful range of the Animac AM-4 warmer and make it useful in pediatric rapid fluid resuscitation and current fluid management. Moreover, they are easy to set up, inexpensive, and can be applied to any kind of blood warmers.

Changes of propofol levels in isolated cardiopulmonary bypass circuit.

BACKGROUND: High dose fentanyl anesthesia in cardiac surgery has been supplemented with propofol to prevent patient's awareness and recall. It has been known that during cardiopulmonary bypass (CPB), fentanyl or midazolam concentration decreases, except for propofol where it remains unknown. This study evaluated the interaction between propofol and the CPB circuit in vitro. METHODS: Three identical experiments were conducted. In each experiment we used a set of CPB circuit composed of a standard 3/8 inch PVC tubing trap, a reservoir and a pump. The reservoir was primed with 2,000 ml solution of 2.5% dextrose and 0.45% NaCl in which 20 mg propofol was added. The solution was circulated in the circuit at a flow rate of 2 L/min. The experimental period was 30 min. A 5 ml sample of the solution was taken from the venous sampling site of the circuit immediately prior to the experiment, and thereafter each from the arterial and venous sampling sites at 1, 3, 5, 10, 20 and 30 min after the start of the experiment. The samples were kept at 4 degrees C and assayed by HPLC. RESULTS: The propofol concentrations decreased exponentially with the increase of experimental time. There were no significant differences in the concentrations and the rates of decrease between the arterial sampling site and the venous sampling site. The decrease was 20% at 1 min, 68% at 10 min, 83% at 20 min, and 92% at 30 min after the beginning of the experiment. CONCLUSIONS: The results demonstrate the presence of propofol sequestration by the CPB circuit. Evaporation in the bubble oxygenator, absorption by and/or adherence to the circuit are suspected as the possible causative factors.