[Construction and preliminary validation of a risk prediction model for the recurrence of diabetic foot ulcer in diabetic patients]

Objective: To develop a risk prediction model for the recurrence of diabetic foot ulcer (DFU) in diabetic patients and primarily validate its predictive value. Methods: Meta-analysis combined with retrospective cohort study was conducted. The Chinese and English papers on risk factors related to DFU recurrence publicly published in China Biology Medicine disc, China National Knowledge Infrastructure, Wanfang Database, VIP Database, and PubMed, Embase, Cochrane Library, and Web of Science, and the search time was from the establishment date of each database until March 31st, 2022. The papers were screened and evaluated, the data were extracted, a meta-analysis was performed using RevMan 5.4.1 statistical software to screen risk factors for DFU recurrence, and Egger's linear regression was used to assess the publication bias of the study results. Risk factors for DFU recurrence mentioned in ≥3 studies and with statistically significant differences in the meta-analysis were selected as the independent variables to develop a logistic regression model for risk prediction of DFU recurrence. The medical records of 101 patients with DFU who met the inclusion criteria and were admitted to Affiliated Hospital of Guizhou Medical University from January 2019 to June 2022 were collected. There were 69 males and 32 females, aged (63±14) years. The receiver operating characteristic (ROC) curve of the predictive performance of the above constructed predictive model for DFU recurrence was drawn, and the area under the ROC curve, maximum Youden index, and sensitivity and specificity at the point were calculated. Dataset including data of 8 risk factors for DFU recurrence and the DFU recurrence rates of 10 000 cases was simulated using RStudio software and a scatter plot was drawn to determine two probabilities for risk division of DFU recurrence. Using the β coefficients corresponding to 8 DFU recurrence risk factors ×10 and taking the integer as the score of coefficient weight of each risk factor, the total score was obtained by summing up, and the cutoff scores for risk level division were calculated based on the total score × two probabilities for risk division of DFU recurrence. Results: Finally, 20 papers were included, including 3 case-control studies and 17 cohort studies, with a total of 4 238 cases and DFU recurrence rate of 22.7% to 71.2%. Meta-analysis showed that glycosylated hemoglobin >7.5% and with plantar ulcer, diabetic peripheral neuropathy, diabetic peripheral vascular disease, smoking, osteomyelitis, history of amputation/toe amputation, and multidrug-resistant bacterial infection were risk factors for the recurrence of DFU (with odds ratios of 3.27, 3.66, 4.05, 3.94, 1.98, 7.17, 11.96, 3.61, 95% confidence intervals of 2.79-3.84, 2.06-6.50, 2.50-6.58, 2.65-5.84, 1.65-2.38, 2.29-22.47, 4.60-31.14, 3.13-4.17, respectively, P<0.05). There were no statistically significant differences in publication biases of diabetic peripheral neuropathy, diabetic peripheral vascular disease, glycosylated hemoglobin >7.5%, plantar ulcer, smoking, multidrug-resistant bacterial infection, or osteomyelitis (P>0.05), but there was a statistically significant difference in the publication bias of amputation/toe amputation (t=-30.39, P<0.05). The area under the ROC curve of the predictive model was 0.81 (with 95% confidence interval of 0.71-0.91) and the maximum Youden index was 0.59, at which the sensitivity was 72% and the specificity was 86%. Ultimately, 29.0% and 44.8% were identified respectively as the cutoff for dividing the probability of low risk and medium risk, and medium risk and high risk for DFU recurrence, while the corresponding total scores of low, medium, and high risks of DFU recurrence were <37, 37-57, and 58-118, respectively. Conclusions: Eight risk factors for DFU recurrence are screened through meta-analysis and the risk prediction model for DFU recurrence is developed, which has moderate predictive accuracy and can provide guidance for healthcare workers to take interventions for patient with DFU recurrence risk.

[Summary of the best evidence on exercise for the prevention and treatment of diabetic foot]

Objective: To summarize the best evidence on exercise for the prevention and treatment of diabetic foot. Methods: A bibliometric approach was used. Systematic searches were carried out to retrieve all the publicly published evidences till July 2022 on exercise for the prevention and treatment of diabetic foot, including guidelines, evidence summary, recommended practices, expert consensus, systematic review, and original research, from foreign language databases including BMJ Best Practice, UpToDate, Joanna Briggs Institute Evidence-Based Practice Database, Cochrane Library, Embase, PubMed, Guideline International Network, National Guideline Clearinghouse, Chinese databases including China National Knowledge Infrastructure, Wanfang Database, VIP Database, China Biology Medicine disc, China Clinical Guidelines Library, and the official websites of relevant academic organizations including National Institute for Health and Care Excellence of the United Kingdom, Registered Nurses' Association of Ontario of Canada, the International Working Group on the Diabetic Foot, International Diabetes Federation, American College of Sports Medicine, American Diabetes Association, and Chinese Diabetes Society. The literature was screened and evaluated for the quality, from which the evidences were extracted and evaluated to summarize the best evidences. Results: Nine guidelines, three expert consensuses, one evidence summary (with two systematic reviews being traced), two systematic reviews, 6 randomized controlled trials were retrieved and included, with good quality of literature. Totally 33 pieces of best evidences on exercise for the prevention and treatment of diabetic foot were summarized from the aspects of appropriate exercise prevention of diabetic foot, exercise therapy of diabetic foot, precautions for exercise, health education, and establishment of a multidisciplinary limb salvage team. Conclusions: Totally 33 pieces of best evidences on exercise for the prevention and treatment of diabetic foot were summarized from 5 aspects, providing decision-making basis for clinical guidance on exercise practice for patients with diabetic foot.

Emergent Majorana zero-modes in an intrinsic anti-ferromagnetic topological superconductor Mn2B2 monolayer

Topological superconductors (TSCs) are an exotic field due to the existence of Majorana zero-modes (MZM) in the edge states that obey non-Abelian statistics and can be used to implement topological quantum computations, especially for two-dimensional (2D) materials. Here we predict manganese diboride (Mn₂B₂) as an intrinsic 2D anti-ferromagnetic (AFM) TSC based on the magnetic and electronic structures of Mn and B atoms. Once Mn₂B₂ ML enters a superconducting state, MZM will be induced by the spin-polarized helical gapless edge states. The Z₂ topological non-trivial properties are confirmed by Wannier charge centers (WCC) and the platform of the spin Hall conductivity near the Fermi level. Phonon-electron coupling (EPC) implies s-wave superconductivity and the critical temperature (T_c) is 6.79 K.

[Minimally invasive enucleation for benign and low-grade malignant pancreatic tumors: an analysis of 60 cases]

Objective: To investigate the safety and feasibility of minimally invasive pancreatic tumor enucleation. Methods: The clinicopathological data of 60 patients with minimally invasive pancreatic tumor enucleation admitted to the Department of Pancreatic Surgery of Fudan University Cancer Center from November 2019 to August 2021 were retrospectively analyzed. There were 17 males and 43 females,with age of (50.0±13.2)years(range: 23 to 73 years). Tumors were located in the head of pancreas in 40 cases(66.7%),neck and tail of pancreas in 20 cases(33.3%). Patients were divided into robotic group(n=25) and laparoscopic group(n=35) according to surgical methods. The measurement data were compared by t-test or Mann-Whitney U test, and the categorical data were compared by χ² test or Fisher exact probability method. The influencing factors of postoperative pancreatic fistula were analyzed by univariate and multivariate Logistic regression. Results: All patients successfully completed tumor enucleation without conversion to laparotomy. The operation time was (183.5±67.3)minutes(range:90 to 410 minutes). Twelve patients(20.0%) underwent stent placement and pancreatic duct repair during operation. The removal time of abdominal drainage tube after operation was (24.7±22.9)days(range:2 to 113 days). The tumor diameter in the robotic group was larger than that in the laparoscopic group((3.5±0.9)cm vs. (2.9±0.7)cm,t=-2.825,P=0.006). The incidences of postoperative biochemical fistula and grade B pancreatic fistula were 20.0%,22.9% and 36.0%,51.4%,respectively(χ²=2.289,P=0.318). There were no grade C pancreatic fistula,lymphatic fistula,biliary fistula,delayed gastric emptying,secondary operation and perioperative death in both groups. Multivariate logistic regression analysis was performed on the occurrence of clinically related pancreatic fistula(above grade B). The results showed that the increase of body mass index(OR=1.285,95%CI:1.053 to 1.569,P=0.014),the larger diameter of the tumor(OR=3.703,95%CI:1.465 to 9.360,P=0.006) and intraoperative pancreatic duct repair(OR=7.889,95%CI:1.471 to 42.296,P=0.016) were independent risk factors,whereas robotic surgery(OR=0.168,95%CI:0.036 to 0.796,P=0.025) was a protective factor. No case of pancreatin dependent dyspepsia and new onset diabetes mellitus was observed. Conclusions: Minimally invasive tumor enucleation is feasible in the treatment of benign and low-grade pancreatic tumors. The incidence of pancreatic fistula is high in the short term after operation,but serious complications are rare. The robot assisted system can reduce the risk of postoperative pancreatic fistula and has more advantages in dealing with larger diameter tumors because of clearer surgical vision and more accurate operation.

[Effects of nitroquine on the development of Plasmodium yoelii at different stages in Anopheles stephensi]

OBJECTIVE

To investigate the effects of nitroquine on the development of different stages of Plasmodium yoelii in Anopheles stephensi.

METHODS

An. stephensi mosquitoes were fed with conventional sucrose water or sucrose water containing 100 μmol/L nitroquine one day prior to P. yoelii infection. Following starvation for 24 hours, mosquitoes were fed with the blood of Kunming mice infected with P. yoelii, and the number of oocysts was observed in the stomach of An. stephensi. After 6 days and 14 days of infection, the mosquitoes were starved for 24 hours, and then fed with conventional sucrose water or nitroquine treated sucrose water. The An. stephensi mosquitoes were starved for 24 hours 6 and 14 days post-infection with P. yoelii, and then fed with conventional sucrose water or nitroquine-containing sucrose water, the numbers of P. yoelii sporozoites were examined in the hemolymph and salivary glands of An. stephensi.

RESULTS

Following exposure to nitroquine-containing sucrose water one day prior to P. yoelii infections, the number of P. yoelii oocysts was significantly lower in the An. stephensi stomach on day 7 (119.2 ± 16.1 vs. 207.3 ± 21.8; t = 3.207, P < 0.05). After conventional sucrose water was ceased for 24 hours on day 6, and An. stephensi was fed with nitroquine-containing sucrose water, the number of P. yoelii sporozoites peaked in the hemolymph on day 14 in the nitroquine treatment group (952.3 ± 22.7) and on day 12 in the sucrose water treatment group (1 287.0 ± 39.0), and there was a significant difference in the number of sporozoites in the salivary glands between the nitroquine treatment group and the sucrose water treatment group (9 467.0 ± 1 304.0 vs. 10 533.0 ± 758.7; t = 0.707, P = 0.506) on day 17. After conventional sucrose water was ceased for 24 hours on day 14, and An. stephensi was fed with nitroquine-containing sucrose water, the number of sporozoites in the salivary glands was significantly greater in the nitroquine treatment group than in the sucrose water treatment group (21 900.0 ± 2 613.0 vs. 10 533.0 ± 732.3; t = 4.188, P < 0.05).

CONCLUSIONS

Nitroquine treatment exhibits diverse effects the development of different stages of P. yoelii, and nitroquine treatment may reduce the transmission of P. yoelii in uninfected An. stephensi.

[Effect of laparoscopic surgery for pancreatic cancer after neoadjuvant chemotherapy]

Objective: To evaluate the safety and feasibility of laparoscopic surgery after neoadjuvant chemotherapy for pancreatic cancer. Methods: Clinical data of 8 patients underwent laparoscopic surgery after neoadjuvant chemotherapy for pancreatic cancer at Fudan University Shanghai Cancer Center from September 2019 to June 2020 were reviewed retrospectively. There were 5 males and 3 females,aged from 47 to 72 years old. All patients underwent abdominal enhanced CT and PET-CT before operation to accurately evaluate the tumor stage and exclude distant metastasis. Results: Neoadjuvant chemotherapy with AG regimen(gemcitabine 1 000 mg/m² and albumin bound paclitaxel 125 mg/m²) was received for 2 to 6 cycles before surgery. All 8 patients successfully completed the operation,including 5 cases of pancreaticoduodenectomy,2 cases of radical antegrade modular pancreatosplenectomy(RAMPS),and 1 case of total pancreatectomy. No conversion to laparotomy or laparoscopic assisted surgery. The operation time was 240 to 450 minutes,the blood loss was 100 to 500 ml,the postoperative length of stay was 10 to 16 days. During the follow-up period up to December 31, 2020, there was 1 case suffered grade B pancreatic leakage and abdominal infection. The numbers of resected lymph nodes were 9 to 31. All patients received R0 resection. The follow-up times were 4.5 to 9.5 months. One patient underwent RAMPS was diagnosed as liver metastasis after 2 months of the operation,and the other 7 patients still survived without tumor recurrence. Conclusion: Minimally invasive surgery of pancreatic cancer after neoadjuvant chemotherapy is safe and feasible in experienced pancreatic minimally invasive centers.

[Development and application of the world's first malaria subunit vaccine RTS, S/AS01]

On October, 2021, the WHO announced the recommendation of RTS, S/AS01 for use among children living in moderately and highly malaria-endemic areas, which receives global attention. Here, the history of RTS, S/AS01 vaccine development and its role in malaria control are described.

UV response characteristics of mixed-phase MgZnO thin films with different structure distributions, high Iuv/Idark ratios, and fast speed MgZnO UV detectors with tunneling breakdown mechanisms

High-performance ultraviolet (UV) detectors with both high responses and fast speeds are hard to make on homogeneous crystal semiconductor materials. Here, the UV response characteristics of mixed-phase MgZnO thin films with different internal structure distributions are studied. The mixed-phase MgZnO-based detector with the given crystal composition has a high response at both deep UV light (96 A W-1 at 240 nm) and near UV light (80 A W-1 at 335 nm). Meanwhile, because of the quasi-tunneling breakdown mechanism within the device, the high-response UV detector also shows a fast response speed (tr = 0.11 μs) and recovery speed (td1 = 26 μs) at deep UV light, which is much faster than both low-response mixed-phase MgZnO-based UV detectors with other structure constitutions and reported high-response UV devices on homogenous crystal materials. The Idark of the device is just 4.27 pA under a 5 V bias voltage, so the signal-to-noise ratio of the device reached 23852 at 5.5 uW cm-2 235 nm UV light. The new quasi-tunneling breakdown mechanism is observed in some mixed-phase MgZnO thin films that contain both c-MgZnO and h-MgZnO parts, which introduce a high response, signal-to-noise ratio, and fast speed into mixed-phase MgZnO-based UV detectors at weak deep UV light.

[The clinical significance of CD(4)(+)CD(69)(+) T lymphocytes in patients with autoimmune hemolytic anemia/Evans syndrome]

Objective: To investigate the significant of peripheral CD(4)(+) CD(69)(+) T lymphocytes in patients with autoimmune hemolytic anemia (AIHA)/Evans syndrome (ES). Methods: In this study peripheral blood samples from 32 patients with AIHA/ES (15 hemolytic episode patients, 17 remission patients) and 13 healthy controls were collected. Patients with AIHA/ES were recruited in Tianjin Medical University General Hospital from October 2015 to May 2016. The percentages of CD(69)(+) T lymphocytes were analyzed by flow cytometry. The expression of CD(69) mRNA in CD(4)(+) T lymphocytes which was sorted from peripheral blood by magnetic activated cell sorting (MACS) was detected using real-time PCR. Soluable CD(69) was measured by ELISA. Results: In hemolytic episode patients, the ratio of CD(3)(+)CD(69)(+)/CD(3)(+)T lymphocytes [(3.08±1.48)%] was significantly higher than that in healthy controls [(1.28±0.83)%, P<0.01] and in remission group[(1.96±1.33)%, P<0.05]. The absolute count of CD(3)(+)CD(69)(+)T lymphocytes in hemolytic episode group [(2.94±1.81)×10(7)/L] was higher than that in healthy controls [(1.48±1.42)×10(7)/L, P<0.05]. The ratio of CD(3)(+)CD(4)(+)CD(69)(+)/CD(3)(+)CD(4)(+)T cells in hemolytic episode group [(2.16±1.56)%] was significantly higher than that in remission group [(1.16±0.62)%, P<0.05] and healthy controls[(0.94±0.78)%, P<0.05]. The quantity of CD(3)(+)CD(4)(+)CD(69)(+)T lymphocytes in hemolytic episode group[(1.04±0.98)×10(7)/L] was higher than in healthy controls [(0.44±0.38)×10(7)/L, P<0.05]. The ratio of CD(3)(+)CD(8)(+)CD(69)(+)/CD(3)(+)CD(8)(+)T lymphocyte in hemolytic episode group [(4.87±2.56)%] was significantly higher than that in healthy controls[(1.83±1.27)%, P<0.01]. The quantity of CD(3)(+)CD(8)(+)CD(69)(+)T lymphocytes in three groups did not show significant difference. The ratio of CD(3)(+)CD(4)(+)CD(69)(+)/CD(3)(+)CD(4)(+) T lymphocytes in hemolytic episode group was negatively correlated with hemoglobin (Hb) (P<0.01) , positively correlated with the percentage of reticulocytes (Ret%) (P=0.01) total bilirubin(TBil), indirect bilirubin(IBil) (P<0.01) and not correlated with absolute reticulocytes count, lactic dehydrogenase (LDH), complement 3(C3), complement 4 (C4). The ratio of CD(3)(+)CD(4)(+)CD(69)(+)/CD(3)(+)CD(4)(+)T lymphocytes in remission group was negatively correlated with Hb (P<0.05). In hemolytic episode patients CD(69) mRNA (32.26±35.11) was significantly higher than that in remission group(6.05±5.87) (P<0.05) and healthy controls (1.76±1.85)(P<0.01). CD(69) mRNA in remission group was significantly higher than healthy controls (P<0.05). Serum CD(69) in hemolytic episode patients [(494.21±16.06) ng/L] was significantly higher than that in healthy controls [(441.39±104.6) ng/L, P<0.05]. Conclusion: Our findings suggest that the proportion of CD(4)(+)CD(69)(+) T lymphocytes increase in AIHA/ES patients, which is correlated with the severity of disease.

[Dynamic investigation of nutritional risk in patients with malignant tumor during hospitalization]

Objective: To prospectively investigate the changes in nutritional status of patients with malignant tumors during hospitalization by using nutritional risk screening (NRS2002), and to analyze the correlation between the nutritional status and clinical outcomes . Methods: This was a prospective and parallel research done by multi-center collaboration from 34 hospitals in China from June to September 2014.Hospitalized patients with malignant tumors inthese departments (Department of Gastroenterology, respiratory medicine, oncology, general surgery, thoracic surgery and geriatrics)were investigated. Only the patients with age≥ 18 years and hospitalization time between 7-30 days were included. During hospitalization, the physical indexes of human bodywere measured, and the NRS 2002 scores, and monitored the nutritional support at the time points of admission and 24 hours before discharge were recorded.And whether there was a nutritional risk in hospitalized patients and its association with clinical outcomes were investigated. Results: A total of 2 402 patients with malignancies were enrolled in this study. Seventy fourpatients who did not complete NRS2002 were eliminated, and 2 328 patients were included. The number of the main diseases was the top five, including 587 cases of colorectal cancer, 567 cases of lung cancer, 564 cases of gastric cancer, 146 cases of esophageal cancer, and 119 cases of liver tumor. At the time of discharge, compared with admission, the BMI, body weight, grip and calf circumferences of patients with malignant tumor were significantly decreased (P<0.05). The total protein, albumin, prealbumin and hemoglobin were significantly lower than those at admission (P<0.05). In 2 328 patients who were completed nutritional risk screening, the rate of malnutrition at admission was 11.1% (BMI =18.5, 258/2 328) and the rate of malnutrition at discharge was 10.9% (BMI =18.5, 254/2 328), there were no significant differences (χ(2)=0.019 7, P=0.888). There were 1 204 patients with nutritional risk at admission (51.7%, NRS2002 score≥3)and 1 352 patients with nutritional risk at discharge (58.1%, NRS2002 score≥3), with significant differences (χ(2)=49.9, P<0.001). The incidence of nutritional risk in patients with colorectal, stomach, and lung tumors at discharge was significantly higher than that at admission (P<0.05). The infective complications and other complications of patients with nutritional risk were significantly greater than those without nutritional risk at admission and at discharge.ICU hospitalization stay of patients with nutritional risk was increased significantly than those without nutritional risk at admission(P=0.042). Hospitalization expenses of patients with nutritional risk was increased significantly than those of patients without nutritional risk at discharge(P<0.01). Conclusion: The patients with malignant tumor have a higher incidence rate of malnutrition at both admission and discharge and malnutritionhas correlation with adverse clinical outcomes.The aboveindicators did not improve significantly at discharge.Doctors should pay more attention to the nutritional status (screening and evaluation)of patients before discharge and use appropriate and adequate nutrition support in order to prevent the weight loss and improve the life quality of patients.

Comprehensive utilization of the pyrolysis products from sewage sludge

Bio-oils were produced from pyrolysis of sewage sludge in a horizontal tubular furnace under the anoxic or anaerobic conditions, by varying operating parameters and moisture content (MC) of the feedstock. Physicochemical properties of the obtained bio-oil (such as density, acid value, kinematical viscosity, high heating value and flash point) were analysed and compared with Chinese fuel standards. Tend, RT and β were found critical to control the yield and physico-chemical properties of bio-oil products. The relative importance of various parameters such as Tend, RT, β and MC was determined and the optimum values for the lowest kinematic viscosity and acid value and the highest yield of the bio-oil were achieved using the orthogonal matrix method. The parameters 550°C, 45 min, 5°C min(-1) and MC of 10% were found effective in producing the bio-oils with most of the desirable physico-chemical properties and yield. Benefit analysis was conducted to further optimize the operating parameters, considering pyrolysis treatment, comprehensive utilization of the pyrolysis products and final disposal of sewage sludge; the results showed the best economy of the pyrolysis parameters 450°C, 75 min, 3°C min(-1) and MC of 10%. The char obtained under this condition may serve as a microporous liquid adsorbent, while the bio-oil may serve as a low grade fuel oil after upgrading it with conventional fuel oil and deacidification. Pyrolysis products may become economically competitive in addition to being environment friendly.

Killing of total heterotrophic bacteria using the gas diffusion electrode system

This study focused on the disinfection of dual electrodes with a gas diffusion cathode using total heterotrophic bacteria as indicator microorganisms. Batch tests were performed to study the effects of platinum load W(Pt) and the pore-forming agent content WNH4HCO3 in gas diffusion electrodes on the germicidal efficacy eta and H2O2 yield. The results showed that the disinfection improved with W(Pt), but its efficiency at W(Pt) of 3 per thousand was equivalent to W(Pt) of 4 per thousand. The right amount of the pore-forming agent improved disinfection. Continuous tests were performed to study residence times (RTs), pH and oxygen flow rates Qo2 on the germicidal efficacy and H2O2 yield. The results indicated that at the steady state total heterotrophic bacteria in the outlet stream were completely inactivated under our experimental conditions. Disinfection improved with increasing RT. This phenomenon was more significant when RT < 20 min. A drop in pH value resulted in the rapid rise of germicidal efficacy, while disinfection shortened with an increasing oxygen flow rate Qo2. The operating costs are high. Further research is required to fully understand all parameters and reduce operating costs.

Killing of Escherichia coli using the gas diffusion electrode system

To be best of our knowledge, this study is one of the first investigations to be performed into the potential benefits of gas diffusion electrode (GDE) system in controlling inactivation of E. coli. This study mainly focused on the dual electrodes disinfection with gas diffusion cathode, using Escherichia coli as the indicator microorganisms. The effects of Pt load W(Pt) and the pore-forming agent content W(NH(4)HCO(3)) in GDE, operating conditions such as pH value, oxygen flow rate Q(O(2)), salt content and current density on the disinfection were investigated, respectively. The experimental results showed that the disinfection improved with increasing Pt load W(Pt), but its efficiency at Pt load of 3 per thousand was equivalent to that at Pt load of 4 per thousand. Addition of the pore-forming agent in the appropriate amount improved the disinfection while drop of pH value resulted in the rapid rise of the germicidal efficacy and the disinfection shortened with increasing oxygen flow rate Q(O(2)). The system is more suitable for highly salt water. The germicidal efficacy increased with current density. However, the accelerating rate was different: it first increased with the current density, then decreased, and reached a maximum at current density of 6.7-8.3 mA/cm(2). The germicidal efficacy in the cathode compartment was about the same as in the anode compartment indicating the contribution of direct oxidation and indirect treatment of E. coli by the hydroxyl radical was similar to the oxidative indirect effect of the generated H(2)O(2). This technology is expensive in operating cost, further research is required to advance the understanding and reduce the operating cost of this technology.

Discoloration of methylene blue and wastewater from a plant by a Fe/Cu bimetallic system

Using a Fe/Cu bimetallic system (Fe/Cu system), the discoloration of both methylene blue in aqueous solution and the colored wastewater from a plant was investigated under the anaerobic condition in batch or continuous reactors. Results show that the Fe/Cu system effectively removed the color with over 88% of color removal efficiency for both methylene blue solution and the wastewater from the plant in batch test. Color removal efficiencies increased rapidly with Fe/Cu dosage and reaction time, respectively, at initial time and slowly to stable values. Optimum pH was neutral range. In addition, in continuous test it also removed the color of the wastewater from the plant with 63% of discoloring efficiency under the condition of 2 h of hydraulic retention time and neutral range of pH (7.0-8.3). High discoloring efficiencies with low chemical oxygen demand removal efficiencies were found in all experiments. The reduction of chromophores in pollutants was the main mechanism of the discoloration in the Fe/Cu system.

Photostability of luminescent ruthenium(II) complexes in polymers and in solution

The effects of oxygen on the photochemical properties of ruthenium(II) complexes in solution and in polymers are reported. In solution, the complex is actually protected from decomposition by the presence of oxygen as a result of deactivation of the complex by oxygen quenching before it can undergo ligand loss by monomolecular dissociation; however, in polymers, the presence of oxygen increases photochemical decomposition. Singlet molecular oxygen, a product of the oxygen quenching process, may attack the ground state complex or triplet oxygen may directly attack the excited state of the complex. Both mechanisms may be involved in the photodestruction of the complex. The role of oxygen in the photodecomposition was examined by monitoring the photochemical decomposition of various complexes of different singlet oxygen reactivity, as well as absorption and mass spectroscopy studies. It is suggested that in polymers, unlike in solutions, the newly formed reactive singlet oxygen is not able to diffuse away from the complex. The singlet oxygen, trapped in close proximity to the metal complex, has an enhanced opportunity to attack it. This cage effect is supported by studies using tris(1,10-phenanthroline)ruthenium(II) in poly(ethylene glycol) of increasing molecular weight to create an increasingly constraining cage around the complex. Increased poly(ethylene glycol) molecular weight leads to increased oxygen attack of the complex, supporting the cage effect.

[Weekly cyclophosphamide pulse therapy combined with corticosteroids in the treatment of pemphigus]

OBJECTIVE

To investigate the better regimen of combined cyclophosphamide pulse therapy with corticosteroids in the treatment of Pemphigus.

METHODS

Intravenous cyclophosphamide was given weekly in a dosage of 600 mg to those Pemphigus patients whose conditions couldn't be improved by corticosteroids (oral prednisone 1.2-1.5 mg/kg/d) alone.

RESULTS

Ten patients with Pemphigus received weekly cyclophosphamide therapy in addition to corticosteroid. Patients conditions improved quickly, without side effects.

CONCLUSIONS

Cyclophosphamide weekly pulse therapy combined with corticosteroids is a good regimen in the treatment of Pemphigus.

Optical fingerprint recognition using a waveguide hologram

We demonstrate the fabrication of a waveguide hologram and describe how a plane-wave output beam can be generated for the illumination of a finger for fingerprint image capture. Also, when using a diverging beam in the substrate as a reference wave, one obtains a set of gratings written in the hologram. The reflected light from the finger is spatially filtered by this hologram, providing bandpassed information back through the waveguide when it is viewed through the plate.

Adaptation of the viral haemorrhagic disease virus of rabbits to the DJRK cell strain

Liver emulsion of rabbits which had died of viral haemorrhagic disease (VHD) was inoculated onto DJRK cell culture. After two passages, specific cytopathic effect was observed. Immunofluorescence was found in the nucleus at the early stage of infection and later also in the cytoplasm. The virus propagated in cell culture at the fifth, tenth and sixteenth passages was found to cause typical VHD. Electron microscopy showed that there were numerous virions in the infected cells. The cultured virus, inactivated with formaldehyde, could elicit haemagglutination inhibition antibodies in the inoculated rabbits and protect them against the challenge of virulent VHD virus.

Viral haemorrhagic disease of rabbits in the People's Republic of China: epidemiology and virus characterisation

Viral haemorrhagic disease (VHD) is a new and severe infectious disease of rabbits, with a high rate of morbidity and mortality. The disease occurs throughout the year, affecting only adult rabbits and not other domestic animals, fowls or laboratory rodents. The transmission is horizontal, by direct or indirect contact, and through all routes. There is no evidence of congenital infection or biological vectors. The causative agent, viral haemorrhagic disease virus (VHDV), is present in all tissues, excretions and secretions. It is an icosahedral and nonenveloped parvo-like virus. The genome, as determined by classical methods, high performance chromatography and in vitro synthesis of double-stranded DNA, is linear, single-stranded DNA. VHDV can agglutinate human erythrocytes at very high titres, irrespective of blood groups, and has a stable reaction to many physical and chemical factors. VHDV has been adapted to grow on rabbit kidney cell strain (DJRK) culture and to produce cytopathic effect (CPE). Inactivated cell culture can protect inoculated rabbits against virulent VHDV. The disease is now effectively controlled in the People's Republic of China, but has not yet been completely eradicated.

Inhibition of human megakaryocytopoiesis in vitro by platelet factor 4 (PF4) and a synthetic COOH-terminal PF4 peptide

We report that highly purified human platelet factor 4 (PF4) inhibits human megakaryocytopoiesis in vitro. At greater than or equal to 25 micrograms/ml, PF4 inhibited megakaryocyte colony formation approximately 80% in unstimulated cultures, and approximately 58% in cultures containing recombinant human IL 3 and granulocyte-macrophage colony-stimulating factor. Because PF4 (25 micrograms/ml) had no effect on either myeloid or erythroid colony formation lineage specificity of this effect was suggested. A synthetic COOH-terminal PF4 peptide of 24, but not 13 residues, also inhibited megakaryocyte colony formation, whereas a synthetic 18-residue beta-thromboglobulin (beta-TG) peptide and native beta-TG had no such effect when assayed at similar concentrations. The mechanism of PF4-mediated inhibition was investigated. First, we enumerated total cell number, and examined cell maturation in control colonies (n = 200) and colonies (n = 100) that arose in PF4-containing cultures. Total cells per colony did not differ dramatically in the two groups (6.1 +/- 3.0 vs. 4.2 +/- 1.6, respectively), but the numbers of mature large cells per colony was significantly decreased in the presence of PF4 when compared with controls (1.6 +/- 1.5 vs. 3.9 +/- 2.3; P less than 0.001). Second, by using the human leukemia cell line HEL as a model for primitive megakaryocytic cells, we studied the effect of PF4 on cell doubling time, on the expression of both growth-regulated (H3, p53, c-myc,and c-myb), and non-growth-regulated (beta 2-microglobulin) genes. At high concentrations of native PF4 (50 micrograms/ml), no effect on cell doubling time, or H3 or p53 expression was discerned. In contrast, c-myc and c-myb were both upregulated. These results suggested the PF4 inhibited colony formation by impeding cell maturation, as opposed to cell proliferation, perhaps by inducing expression of c-myc and c-myb. The ability of PF4 to inhibit a normal cell maturation function was then tested. Megakaryocytes were incubated in synthetic PF4, or beta-TG peptides for 18 h and effect on Factor V steady-state mRNA levels was determined in 600 individual cells by in situ hybridization. beta-TG peptide had no effect on FV mRNA levels, whereas a approximately 60% decrease in expression of Factor V mRNA was found in megakaryocytes exposed to greater than or equal 100 ng/ml synthetic COOH-terminal PF4 peptide. Accordingly, PF4 modulates megakaryocyte maturation in vitro, and may function as a negative autocrine regulator of human megakaryocytopoiesis.

Immunological studies on thromboangiitis obliterans

Using humoral immunity (gamma-globulin 18 cases, IgG, IgA, IgM each 30 cases, CH50, C3, C4 each 29 cases and CIC 31 cases), cellular immunity (E-RFC 68 cases, As 30 cases, SmIg, SmIgG each 18 cases, IMIT 30 cases) and immunopathological manifestations (light microscope, fluorescence microscope, transmitted electron microscope each 7 cases) as indices, we studied the immunological changes of "progressing", "remittent" and "stabilized" groups of patients with thromboangiitis obliterans (TAO) in different stages. Humoral immunity indicated that gamma-globulin, immune complex and IgG were all increased; cellular immunity indicated that the rate of T cells and suppressor cells was declined, while that of B cells was elevated. Immunopathologically, under light microscope all the layers of involved vessels were infiltrated with neutrophils, lymphocytes and monocytes; under fluorescence and electron microscope, immune complexes were found in the involved vessel walls. Our preliminary results suggest that TAO is an autoimmune disease relevant to antigen-antibody complex.

Role of natural killer cells, in comparison with T lymphocytes and monocytes, in the regulation of normal human megakaryocytopoiesis in vitro

Natural killer (NK) cells are thought to play an important role in host defense against virus-infected and neoplastic cells. Recent reports suggest that these cells may also influence developmental events in the course of normal erythropoiesis and granulopoiesis. The role of NK cells in the regulation of normal human megakaryocytopoiesis has not been reported, but clinical observations suggest that NK cell effects on megakaryocyte progenitors might differ from those of other cell lineages. We therefore carried out in vitro studies designed to assess the influence of NK cells on the growth of autologous megakaryocyte colony-forming units (CFU-Meg). To provide a frame of reference for these experiments, the effect of T lymphocytes, and monocyte-macrophages (M luminal diameter) on autologous CFU-Meg cloning efficiency was also studied. Purified immune effector cells were co-cultured in plasma clots with both unseparated, and progenitor cell-enriched marrow mononuclear cells (MNC) at target to effector cell ratios varying from 100:1 to 1:1. Resulting megakaryocyte colonies were enumerated by indirect fluorescence microscopy by using a rabbit anti-human platelet glycoprotein antiserum as probe for cells of the megakaryocyte lineage. The addition of NK cells to both unseparated (n = 12), and progenitor-enriched (n = 3) MNC at target to effector cell ratios of 2:1 and 1:1 resulted in a significant (p less than 0.05) augmentation in CFU-Meg-derived colony formation. Augmentation of colony formation was blocked by incubating the NK cells in Leu-11b monoclonal antibody. Stimulation appeared to be carried out by the production of a soluble growth factor which was detectable in NK cell-conditioned medium. Exposure of NK cells for 18 hr to highly purified or recombinant gamma-interferon (500 U/10(6) cells), a putative NK cell stimulator, neither increased nor abrogated the stimulatory effect. The latter could be accomplished, however, by centrifuging (200 X G for 5 min), and then preincubating the target and effector cells together for 3 hr before plating. At no time was significant inhibition of CFU-Meg demonstrated. In contrast to these results, when tested at the same ratios, and under the same conditions, no consistent effect on CFU-Meg cloning efficiency could be demonstrated by the addition of whole T cells, T cell subsets, or M luminal diameter. These results suggest that NK cells could play a role in the basal regulation of megakaryocytopoiesis.(ABSTRACT TRUNCATED AT 400 WORDS)

Role of natural killer cells, in comparison with T lymphocytes and monocytes, in the regulation of normal human megakaryocytopoiesis in vitro

Natural killer (NK) cells are thought to play an important role in host defense against virus-infected and neoplastic cells. Recent reports suggest that these cells may also influence developmental events in the course of normal erythropoiesis and granulopoiesis. The role of NK cells in the regulation of normal human megakaryocytopoiesis has not been reported, but clinical observations suggest that NK cell effects on megakaryocyte progenitors might differ from those of other cell lineages. We therefore carried out in vitro studies designed to assess the influence of NK cells on the growth of autologous megakaryocyte colony-forming units (CFU-Meg). To provide a frame of reference for these experiments, the effect of T lymphocytes, and monocyte-macrophages (M luminal diameter) on autologous CFU-Meg cloning efficiency was also studied. Purified immune effector cells were co-cultured in plasma clots with both unseparated, and progenitor cell-enriched marrow mononuclear cells (MNC) at target to effector cell ratios varying from 100:1 to 1:1. Resulting megakaryocyte colonies were enumerated by indirect fluorescence microscopy by using a rabbit anti-human platelet glycoprotein antiserum as probe for cells of the megakaryocyte lineage. The addition of NK cells to both unseparated (n = 12), and progenitor-enriched (n = 3) MNC at target to effector cell ratios of 2:1 and 1:1 resulted in a significant (p less than 0.05) augmentation in CFU-Meg-derived colony formation. Augmentation of colony formation was blocked by incubating the NK cells in Leu-11b monoclonal antibody. Stimulation appeared to be carried out by the production of a soluble growth factor which was detectable in NK cell-conditioned medium. Exposure of NK cells for 18 hr to highly purified or recombinant gamma-interferon (500 U/10(6) cells), a putative NK cell stimulator, neither increased nor abrogated the stimulatory effect. The latter could be accomplished, however, by centrifuging (200 X G for 5 min), and then preincubating the target and effector cells together for 3 hr before plating. At no time was significant inhibition of CFU-Meg demonstrated. In contrast to these results, when tested at the same ratios, and under the same conditions, no consistent effect on CFU-Meg cloning efficiency could be demonstrated by the addition of whole T cells, T cell subsets, or M luminal diameter. These results suggest that NK cells could play a role in the basal regulation of megakaryocytopoiesis.(ABSTRACT TRUNCATED AT 400 WORDS)