Research on energy-saving factors adaptability of exterior envelopes of university teaching-office buildings under different climates (China) based on orthogonal design and EnergyPlus.

To achieve carbon neutrality in 2060 (China), building energy-saving has been highly concerned. University buildings have great energy-saving potential as part of energy consumption where 70% of energy loss is caused by heat transfer from the envelope. However, most of the research on energy-saving factors for envelopes is limited to a certain climate or a specific building type, and the optimal configuration of envelopes under different climatic regions has not been well solved. Therefore, the influence degree and appropriate parameters of each factor of the teaching-office building envelopes on energy consumption under different climates were analyzed in this paper by orthogonal design and numerical simulation. Results show that: (1) Solar heat gain coefficient (SHGC) and indoor air change rates (ACH) [the heat transfer coefficient of the exterior wall (K wall ) and ACH] are the main factors affecting the cooling [heating] load, the insulation form of the exterior wall (W ins ) and K wall [W ins and solar radiation absorption coefficient of exterior surface materials (ρ s )] have less influence; (2) The important ranking and optimal level of the influence of each factor on the cooling (or heating) loads are related to local load demands; (3) For the annual load, K wall and the heat transfer coefficient of the exterior window (K win ) is the focus of energy-saving in severe cold and cold zones, but their impact is not significant in Guangzhou and Kunming, and the high significance of SHGC is only shown in Hohhot, Lhasa, Guangzhou, and Haikou; (4) The annual load energy savings reach 39.64%-57.57% in different climates by optimizing all factors. The research results can provide directions and data references for the energy-saving design and renovation of educational building envelopes in different climates (China).

[Analysis on the diagnosis and treatment of necrotizing fasciitis complicated with sepsis].

OBJECTIVE: To recognize the characteristics of necrotizing fasciitis patients complicated with sepsis and summarize the experience the treatment. METHODS: A retrospective study was conducted. The clinical data of 57 patients with necrotizing fasciitis complicated with sepsis admitted to Guangdong Provincial People's Hospital from July 2009 to December 2019 was analyzed by collecting such factors as gender, age, complications, infection sites, pathogens, surgery information, treatment options and outcome. The patients were divided into debridement group (n = 14) and control group (n = 43) according to whether the debridement was completed within 48 hours of admission, and the mortality during hospitalization between the two groups was compared. A telephone follow-up had been done to record the long-term outcome of these patients. RESULTS: Among 57 patients with necrotizing fasciitis complicated with sepsis, there were 43 males and 14 females with the average age of (57.9±12.1) years old. Most of the underlying diseases were diabetes mellitus (70.17%), other diseases included hypertension (8.77%), tumor chemotherapy (7.02%), liver disease (hepatitis, cirrhosis, 7.02%), coronary artery heart disease (3.51%), systemic lupus erythematosus (3.51%), etc. Most of the infection site was lower limbs (71.93%). There were 78 pathogens cultured in 57 patients, in which 52 were non-drug resistant bacteria (66.67%), and 26 were drug resistant bacteria (33.33%). There were 40 Gram positive (G+) bacteria (51.28%), 29 Gram negative (G-) bacteria (37.18%), 8 fungi (10.26%) and 1 mixed bacteria (1.28%). Finally, of 57 patients, 46 patients were cured, and 11 patients died with hospital mortality of 19.30%. Among 57 patients, the hospital mortality in the debridement group was significantly lower than that in the control group [0% (0/14) vs. 25.58% (11/43), P < 0.05]. Among the 46 cured patients, 11 had accepted amputations, accounting for 23.91%. In December 2020, 43 patients who were cured (3 patients were lost to follow-up) were followed up by telephone. Twenty-three patients were completely self-care, 9 patients were partly self-care, 8 patients were completely unable to take care of themselves, and 3 patients died. CONCLUSIONS: Necrotizing fasciitis with sepsis mostly occurs in people with weakened immunity, and has a high mortality and disability rate. Early identification and active surgical debridement may be the key to improve the treatment effect.

Effect of bone marrow mesenchymal stem cells on the polarization of macrophages.

Inflammation is a defensive response in the living tissue of the vascular system that acts against damage factors and involves various types of immune cells, including macrophages, neutrophils, endothelial cells and other associated immune molecules. If the release of inflammatory mediators is excessive, systemic inflammatory response syndrome may develop. Sepsis is the most common complication of severe burns and is a systemic inflammatory response syndrome that is caused by infectious factors and is capable of leading to multiple organ dysfunction and potentially death. Research concerning the mechanism and treatment of sepsis is crucial. Macrophages are an important type of immune cell that remove invasive pathogens and are involved in innate and adaptive immune responses. It has been previously reported that bone marrow mesenchymal stem cells (BMSCs) affect macrophages by regulating immunity. The present study aimed to investigate the effect of BMSCs on macrophage polarization in vivo and in vitro, in addition to the potential therapeutic effect of these cells on experimental sepsis. BMSCs and peritoneal macrophages were isolated from Sprague­Dawley rats and co­cultured overnight as a mixed culture or Transwell system, and subsequently stimulated with 100 ng/ml lipopolysaccharide (LPS). After 12 h, the medium was replaced with normal complete medium for various durations and supernatants were collected to extract proteins and cells for ELISA, western blot and flow cytometry analysis to investigate different aspects of macrophages. Sepsis was induced in Sprague­Dawley rats by injection of LPS (5 mg/kg), followed by tail vein injection of BMSCs or PBS 1 h later. After 6, 12, 24 and 48 h, lung tissues were harvested for pathological observation and peritoneal macrophages were collected for flow cytometry analysis to assess the expression of markers, including cluster of differentiation (CD)68 (used for gating), CD11c and CD206. The results demonstrated that, in the culture medium, LPS stimulation increased the expression of CD11c in macrophages, and the levels of tumor necrosis factor­α and inducible nitric oxide synthase were also increased. By contrast, in macrophages treated with BMSCs directly, the expression of CD11c was reduced compared with the LPS­stimulated macrophage alone group. However, the secretion of interleukin­10, transforming growth factor­ß and arginase­1 was increased in the direct co­culture group, compared with the LPS­stimulated macrophage alone group. BMSCs reduced the inflammation in lung tissues and inhibited macrophage expression of CD11c in the rat model of sepsis. The results of the present study demonstrated that BMSCs co­cultured with macrophages directly inhibited macrophage differentiation into the M1 phenotype and reduced inflammation in macrophages stimulated by LPS. In vivo, BMSCs decreased the expression of CD11c in peritoneal macrophages and reduced the pathological inflammatory response in the lungs. The findings of the present study demonstrated that BMSCs may reduce the extent of the systemic inflammatory response, which may contribute to the development for a novel type of treatment for sepsis in the future.

[Analysis of liver damage and reactivation of hepatitis B virus in hepatitis B surface antigen positive patients after extremely severe burn injury].

OBJECTIVE: To analyze the development of liver damage and reactivation of hepatitis B virus (HBV) during the treatment of extremely severe burn injury in HBsAg positive patients, in order to provide reference for prevention and treatment of liver damage in patients with HBV infection after extremely severe burn. METHODS: Medical records of 54 HBsAg positive patients after extremely severe burn injury admitted from January 2004 to December 2014 were retrospectively analyzed. Development of liver damage and HBV reactivation of these patients during the treatment were analyzed according to the classification of their gender, results of hepatitis B e antigen (HBeAg) and HBV DNA examinations on admission, and development of sepsis in the process of treatment. Data were processed with chi-square test. RESULTS: (1) The incidence of liver damage in the process of treatment of these patients was 85.2% (46/54). Among all the patients, the proportion of liver damage was 35/38 in male, which was significantly higher than that in female (11/16, χ² = 4.867, P<0.05). Liver damage was found in all of 26 patients who were HBeAg positive on admission, 34 patients who were HBV DNA positive on admission, and 36 patients who developed sepsis in the process of treatment; the proportions were significantly higher than those in patients who were HBeAg negative on admission (20/28), patients who were HBV DNA negative on admission (12/20), and patients who did not develop sepsis in the process of treatment (10/18), with χ² values respectively 11.801, 18.384, and 20.574, P values below 0.01. (2) The incidence of HBV reactivation in these patients was 29.6% (16/54). Among all the patients, the proportion of HBV reactivation was 13/38 in male and 3/16 in female, with no statistically significant difference between them (χ² = 0.656, P>0.05). The proportions of HBV reactivation in patients who were HBeAg positive on admission, patients who were HBV DNA positive on admission, and patients who developed sepsis in the process of treatment were respectively 13/26, 16/34, and 15/36, and they were significantly higher than those in patients who were HBeAg negative on admission (3/28), patients who were HBV DNA negative on admission (0/20), and patients who did not develop sepsis in the process of treatment (1/18), with χ² values respectively 9.979, 18.615, and 5.873, P<0.05 or P<0.01. CONCLUSIONS: Patients who are HBsAg positive, HBeAg positive, HBV DNA positive on admission, and develop sepsis in the process of treatment of extremely severe burn injury are more likely to develop liver damage and HBV reactivation. It is necessary to dynamically monitor the changes in HBV DNA and liver function, in order to identity the reactivation of virus.

[Classification and management of sternal wound complications after cardiac surgery].

OBJECTIVE: To define the classification of sternal wound complications after cardiac surgery and to explore the appropriate surgical treatment. METHODS: Between July 2008 and January 2014, 260 patients with sternal wound complications after cardiac surgery were treated. There were 124 males and 136 females, aged 11-75 years (mean, 49.5 years). The disease duration was 13-365 days (mean, 26.6 days) with a wound length of 1-25 cm (mean, 13.4 cm). The wounds were divided into type I (n = 70), type II (n = 64), type III (n = 42), type IV (n = 78), and type V (n = 6) according to self-generated classification for sternal wound complications after cardiac surgery. After debridement, wounds of type I and type II were repaired with local flap transplantation; wounds of type III were repaired with local flap transplantation combined with butterfly sternal fixation (n = 28), with bilateral pectoralis muscle flap combined with butterfly sternal fixation (n = 11), and with bilateral pectoralis muscle flap (n = 3); wounds of type IV were repaired with bilateral pectoralis muscle flap (n = 65), rectus abdominis muscle flap (n = 5), and pedicled omental flap (n = 8); and wounds of type V were repaired with pedicled omental flap. RESULTS: All the operations were successfully performed. Three patients died after pedicled omental flap repair, including 1 case of type IV and 2 cases of type V. The hospitalization time were 4-86 days (mean, 18.3 days). Primary wound healing was obtained in 248 cases (96.5%); poor healing occurred in 9 patients, which were cured after second surgery in 8 cases and after the third surgery in 1 case. CONCLUSION: The surgical treatment based on self-generated classification is appropriate to sternal wound complications after cardiac surgery. It can provide clinical evidence for the choice of subsequent operation.

[Clinical application of low-molecular-weight heparin (Fraxiparine) in rescuing venous crisis of island skin flap].

OBJECTIVE: To evaluate the clinical efficacy of low molecular weight heparin (Fraxiparine) in rescuing venous crisis of island skin flap. METHODS: Of the 73 patients with venous crisis of island skin flap, 47 received subcutaneous injection of low-molecular-weight heparin (group I) and 26 were treated with phlebotomy, local compression and topical application of unfractionated heparin solution gauze (group II). RESULTS: The flap survival ratio was (88.46∓8.64)% in group I and (38.37∓6.53)% in group II (P<0.001). At 0, 2, and 4 h after injection of low-molecular-weight heparin, the activated partial thromboplastin time (APTT) was obviously delayed (24.28∓6.71, 41.35∓7.64 and 32.34∓6.35, respectively, P<0.01), FXa:C level was significantly decreased (152.4∓30.7, 65.8∓24.4 and 83.4∓18.4, respectively, P<0.01), while FIIa:C level underwent no obvious alterations (155.70∓31.61, 143.20∓24.75, and 143.4∓23.35, respectively, P=NS). CONCLUSION: Fraxiparine has good antithrombotic efficacy in rescuing venous crisis of island skin flap without adverse effect on systemic coagulation.

[Establishment of a rat model of bone marrow mesenchymal stem cell transplantation for repairing full-thickness skin defect].

OBJECTIVE: To establish a rat model of full-thickness skin defect to receive bone marrow mesenchymal stem cell transplantation for wound repair. METHODS: A full-thickness skin defect measuring 4 cmx4 cm in 36 F344 rats, which were divided into 3 groups with the wound covered with alloskin graft, acellular dermal matrix, or petrolatum gauze. In vitro cultured BMSCs in the 5th passage were transplanted into the skin defect, and the time of wound dressing dissociation and number of transplanted Brdu-positive cells in the wound were observed 14 days later. RESULTS: The alloskin graft resulted in significantly longer time before dressing dissociation, with greater number of Brdu-positive cells in the wound than the other two wound dressings (P<0.001). The acellular dermal matrix showed better effect than petrolatum gauze in terms of the dressing dissociation time and the viable transplanted cell number in the wound. CONCLUSION: Alloskin graft can be ideal for covering the wound surface to protect the transplanted BMSCs in rats.

[Establishing a parabiosis animal model of two-way paradigm].

OBJECTIVE: To establish a parabiosis model between allogenic conspecific adult mice to study two-way paradigm. METHODS: Fifty-four female Balb/c mice and 54 male C57BL/6 mice were paired and equally divided into 3 groups, namely group 1 with normal saline (NS) injection, group 2 with injections of spleen cells and cyclophosphamide (CP), and group 3 injected with spleen cells, CP, and cyclosporin A (CsA). The treatments were performed by injecting the spleen cells from one of the mice in a pair into the other via tail vein and vise versa, and two days after the operation, CP (150 mg/kg) was injected intraperitoneally. Intraperitoneal CsA (30 mg/kg daily) injection was given starting from 2 days before till 7 days after the operation. Twelve of the 18 pairs of parabiosis mice in each group were separated after 1 week, and part of the skin were transplanted to each other. The maintenance of parabiosis was observed in the other 6 pairs of parabiosis mice were observed. Mixed lymphocyte reaction (MLR) and delayed-type hypersensitivity (DTH) were observed and studied in the separated mice. RESULT: The duration of parabiosis maintenance and skin survival of the group 3 was significantly longer than those in the other two groups, and group 3 showed suppressed MLR and DTH. CONCLUSION: With the application of immunosuppressants, we have successfully established the two-way paradigm model in mice.