Development of a Cost-Effective 3D-Printed Airway Suction Simulator for Respiratory Therapy Students

BACKGROUND

Three-dimensional (3D)-printed models are cost-effective and can be customized by trainers. This study designed a 3D-printed airway suction simulator for use by respiratory therapy (RT) students. The objective was to demonstrate the cost-effectiveness and application of 3D-printed models in respiratory care training, aiming to enhance the educational experience for RT students.

METHODS

This study developed a 3D-printed airway suction simulator that was cost-effective. A randomized controlled trial was conducted involving RT students to compare effectiveness in a 3D-model group and a control group. Skill assessments and written examinations were used to evaluate the participants' knowledge and skills.

RESULTS

A total of 38 second-year RT students were randomly assigned to either the 3D-model group (n = 19) or the control group (n = 19). One participant in the 3D-model group was lost to follow-up during the planned direct observation of procedural skills (DOPS) assessment and satisfaction questionnaire completion. The posttest written examination scores were significantly higher in the 3D-model group than in the control group (100% vs 80%, P = .02). The scores from the DOPS and satisfaction questionnaire were comparable in the 2 groups.

CONCLUSIONS

This study demonstrated that 3D printing can be used to create a safe and cost-effective airway suction simulator for use by RT students, with potential to enhance training methods. Further research is necessary.

Limosilactobacillus reuteri peptidoglycan alleviates aflatoxin B1-induced toxicity through adsorbing toxins and improving growth, antioxidant status, immunity and liver pathological changes in chicks

1. The objective of this study was to investigate the protective effects of a peptidoglycan produced by Limosilactobacillus reuteri against aflatoxin B1 (AFB1) induced toxicity in vitro and in vivo in broiler chicks.2. Toxin adsorption experiments were carried out firstly in vitro. These experiments indicated that the absorption efficiency of the peptidoglycan for AFB1 was 64.3-75.9%.3. In the in vivo experiments, Hy-Line Brown chicks were fed a diet containing AFB1 at 71.43 µg/kg with and without peptidoglycan supplementation at concentrations of 100, 200, or 300 g/kg feed from 0-42 d of age.4. The peptidoglycan supplementation in AFB1-contaminated diets resulted in significant improvements in terms of average daily gain, feed intake, feed conversion ratio, white blood cell count, haemoglobin content, glutathione peroxidase activity, immunoglobulin (Ig) A, IgG, IgM and Newcastle disease virus antibody titres (p < 0.05) and diminished liver steatosis.5. In conclusion, peptidoglycan supplementation alleviated AFB1-induced toxicity through adsorbing toxins and improving growth performance, antioxidant ability, immunity and liver pathological changes in chicks. The optimal supplemental dose was 200 mg/kg in feed.

[Efficacy and safety of extracorporeal membrane oxygenation-supported percutaneous coronary intervention in chronic coronary total occlusion patients with reduced left ventricular ejection fraction]

Objective: To investigate the feasibility and safety of extracorporeal membrane oxygenation (ECMO)-supported percutaneous coronary intervention (PCI) in chronic coronary total occlusion (CTO) patients with reduced left ventricular ejection fraction (LVEF). Methods: The CTO patients with LVEF≤35% and undergoing CTO-PCI assisted by ECMO in the General Hospital of Northern Theater Command from December 2018 to March 2022 were enrolled in this study. The post-procedure complications, changes of LVEF from pre-procedure to post-procedure during hospitalization, and the incidence of all-cause mortality and changes of LVEF after discharge were assessed. Results: A total of 17 patients aged (59.4±11.8) years were included. There were 14 males. The pre-procedure LVEF of these patients were (29.00±4.08)%. Coronary angiography results showed that there were 29 CTO lesions in these 17 patients. There was 1 in left main coronary artery, 7 in left anterior descending artery, 11 in left circumflex artery, and 10 in right coronary artery. ECMO was implanted in all patients before procedure. Among 25 CTO lesions attempted to cross, 24 CTO were successfully implanted with stents. All patients underwent successful PCI for at least one CTO lesion. The number of drug-eluting stents implantation per patient were 4.6±1.3. After procedure, there were 8 patients with hemoglobin decreased>20 g/L, and 1 patient with ECMO-access-site related bleeding. The LVEF value at a median duration of 2.5 (2.0-5.5) days after procedure significantly increased to (38.73±7.01)% (P<0.001 vs. baseline). There were no in-hospital deaths. Patients were followed up for 360 (120, 394) days after discharge, 3 patients died (3/17). The LVEF value was (41.80±7.32)% at 155 (100, 308) days after discharge, which was significantly higher than the baseline value (P<0.001). Conclusion: The results of present study demonstrate that it is feasible, efficient and safe to perform ECMO)-supported CTO-PCI in CTO patients with reduced LVEF.

[Clinical characteristics and prognostic analysis of female patients with Stanford type B aortic dissection]

Objective: To explore the clinical characteristics and prognostic factors of female patients with Stanford type B aortic dissection. Methods: This is a single-centre retrospective study. Consecutive patients diagnosed with Stanford type B aortic dissection in General Hospital of Northern Theater Command from June 2002 to August 2021 were enrolled, and grouped based on sex. According to the general clinical conditions and complications of aortic dissection tear, patients were treated with thoracic endovascular aortic repair, surgery, or optimal medication. The clinical characteristics and aortic imaging data of the patients at different stages were collected, adverse events including all-cause deaths, stroke, and occurrence of aortic-related adverse events were obtained during hospitalization and within 30 days and at 1 and 5 years after discharge. According to the time of death, death was classified as in-hospital death, out-of-hospital death, and in-hospital death was divided into preoperative death, intraoperative death and postoperative death. According to the cause of death, death was classified as aortic death, cardiac death and other causes of death. Aortic-related adverse events within 30 days after discharge included new paraplegia, post-luminal repair syndrome, and aortic death; long-term (≥1 year after discharge) aortic-related adverse events included aortic death, recurrent aortic dissection, endoleak and distal ulcer events. The clinical characteristics, short-term and long-term prognosis was compared between the groups. Logistic regression analysis was used to explore the association between different clinical factors and all-cause mortality within 30 days in female and male groups separately. Results: A total of 1 094 patients with Stanford type B aortic dissection were enrolled, mean age was (53.9±12.1) years, and 861 (78.7%) were male and 233 (21.3%) were female. (1) Clinical characteristics: compared with male patients, female patients were featured with older average age, higher proportion of aged≥60 years old, back pain, anemia, optimal medication treatment, and higher cholesterol level; while lower proportion of smoking and drinking history, body mass index, calcium antagonists use, creatine kinase level, and white blood cell count (all P<0.05). However, there was no significant difference in dissection tear and clinical stage, history of coronary heart disease, diabetes, hypertension, and cerebrovascular disease between female and male patients (all P>0.05). (2) Follow-up result: compared with male patients, female patients had a higher rate of 30-day death [6.9% (16/233) vs. 3.8% (33/861), P=0.047], in-hospital death (5.6% (13/233) vs. 2.7% (23/861), P=0.027), preoperative death (3.9% (9/233) vs. 1.5% (12/861), P=0.023) and aorta death (6.0% (14/233) vs. 3.1% (27/861), P=0.041). The 1-year and 5-year follow-up results demonstrated that there were no significant differences in death, cerebrovascular disease, and aorta-related adverse events between the two groups (all P>0.05). (3) Prognostic factors: the results of the univariate logistic regression analysis showed that body mass index>24 kg/m² (HR=1.087, 95%CI 1.029-1.149, P=0.013), history of anemia (HR=2.987, 95%CI 1.054-8.468, P=0.032), hypertension (HR=1.094, 95%CI 1.047-1.143, P=0.040) and troponin-T>0.05 μg/L (HR=5.818, 95%CI 1.611-21.018, P=0.003)were associated with an increased risk of all-cause mortality within 30 days in female patients. Conclusions: Female patients with Stanford type B aortic dissection have specific clinical characteristics, such as older age at presentation, higher rates of anemia and combined back pain, and higher total cholesterol levels. The risk of death within 1 month is higher in female patients than in male patients, which may be associated with body mass index, hypertension, anemia and troponin-T, but the long-term prognosis for both female and male patients is comparable.

Highly Organized Porous Gelatin-Based Scaffold by Microfluidic 3D-Foaming Technology and Dynamic Culture for Cartilage Tissue Engineering

A gelatin-based hydrogel scaffold with highly uniform pore size and biocompatibility was fabricated for cartilage tissue engineering using microfluidic 3D-foaming technology. Mainly, bubbles with different diameters, such as 100 μm and 160 μm, were produced by introducing an optimized nitrogen gas and gelatin solution at an optimized flow rate, and N₂/gelatin bubbles were formed. Furthermore, a cross-linking agent (1-ethyl-3-(3-dimethyl aminopropyl)-carbodiimide, EDC) was employed for the cross-linking reaction of the gelatin-based hydrogel scaffold with uniform bubbles, and then the interface between the close cells were broken by degassing. The pore uniformity of the gelatin-based hydrogel scaffolds was confirmed by use of a bright field microscope, conjugate focus microscope and scanning electron microscope. The in vitro degradation rate, mechanical properties, and swelling rate of gelatin-based hydrogel scaffolds with highly uniform pore size were studied. Rabbit knee cartilage was cultured, and its extracellular matrix content was analyzed. Histological analysis and immunofluorescence staining were employed to confirm the activity of the rabbit knee chondrocytes. The chondrocytes were seeded into the resulting 3D porous gelatin-based hydrogel scaffolds. The growth conditions of the chondrocyte culture on the resulting 3D porous gelatin-based hydrogel scaffolds were evaluated by MTT analysis, live/dead cell activity analysis, and extracellular matrix content analysis. Additionally, a dynamic culture of cartilage tissue was performed, and the expression of cartilage-specific proteins within the culture time was studied by immunofluorescence staining analysis. The gelatin-based hydrogel scaffold encouraged chondrocyte proliferation, promoting the expression of collagen type II, aggrecan, and sox9 while retaining the structural stability and durability of the cartilage after dynamic compression and promoting cartilage repair.

Evaluation and Preparation of a Designed Kartogenin Drug Delivery System (DDS) of Hydrazone-Linkage-Based pH Responsive mPEG-Hz-b-PCL Nanomicelles for Treatment of Osteoarthritis

Osteoarthritis (OA) is a chronic disease caused by the damage of articular cartilage. Kartogenin (KGN) is a well-recognized small molecule which could induce MSCs chondrogenesis and promote cartilage repair treatments. Nano-level micells could be a suitable drug carrier technology for the treatments. In this study, the acid-responsive methoxy poly(ethylene oxide)-hydrazone-poly(ε-caprolactone) copolymers, mPEG-Hz-b-PCL, were synthesized. The structure was characterized by ¹H NMR. The evaluation of a designed kartogenin drug delivery system (DDS) of hydrazone-linkage-based pH responsive mPEG-Hz-b-PCL nanomicelles for treatment of osteoarthritis could be carried out.

Characterization of Composite Nano-Bioscaffolds Based on Collagen and Supercritical Fluids-Assisted Decellularized Fibrous Extracellular Matrix

Nano-bioscaffolds obtained from decellularized tissues have been employed in several medical applications. Nano-bioscaffolds could provide structural support for cell attachment and a suitable environment with sufficient porosity for cell growth and proliferation. In this study, a new combined method constitutes a decellularization protocol to remove the tissue and cellular molecules from porcine dermis for preparation of nano-bioscaffolds with fibrous extracellular matrix via pre- and post-treatment of supercritical fluids. The supercritical fluids-assisted nano-bioscaffolds were characterized by peptide identification, infrared spectrum of absorption, morphology, histological observations, DNA quantification, and hemocompatibility. Further, the resulting nano-bioscaffolds could be employed to obtain new cross-linked composite nano-bioscaffold containing collagen and acellular matrix.

[Key data elements for clinical management and outcomes of patients with coronary artery disease: definitions from Coronary Artery Disease and Creative Antithrombotic Clinical Research Collaboration (CardiaCare)]

Objective: To develop a set of data elements and standardized definitions of Coronary Artery Disease and Creative Antithrombotic Clinical Research Collaboration (CardiaCare), aiming to facilitate the exchange of disparate data sources, enhance the abilities to support multicenter researches, and subsequently ensure the databases use under standardized process and criteria. Methods: The Cardiacare writing committee members reviewed data elements and definitions from published guidelines, clinical trials, databases, and standardized documents, then determined the data elements and standardized definitions, which should be included in CardiaCare. The writing committee also considered the specific domestic clinical management strategies during the establishment of Cardiacare. The resulting documents provide a series of key data elements and standardized definitions used in the management of coronary artery disease patients. Key data elements from CardiaCare could be sorted by clinical management flowsheet and outcome from hospitalization to long-term follow-up. Results: The Cardiacare standardized set comprised 864 data elements from admission to post-hospital follow-up visit. There were 8 tables in the documents, including demographic and admission information (23 elements), medical history and risk factors (102 elements), clinical presentations and diagnosis (22 elements), diagnostic and laboratory tests (111 elements), interventional diagnosis and treatment (118 elements), pharmacological therapy (213 elements), clinical outcomes (161 elements), and special subpopulations (114 elements: 87 elements for transcatheter valve replacement and 27 elements with cardiac rehabilitation). Conclusions: The Cardiacare standardized data elements set could provide support for real-world clinical research in consecutive data collection and databases mining. A wider applicability in various settings of CardiaCare needs to be explored further.

Efficacy Analysis of In Situ Synthesis of Nanogold via Copper/Iodonium/Amine/Gold System under a Visible Light

This article presents, for the first time, the kinetics and the general features of a photopolymerization system (under visible light), copper-complex/Iodonium/triethylamine/gold-chloride (orA/B/N/G), with initial concentrations of A0, B0, N0 and G0, based on the proposed mechanism of Tar et al. Analytic formulas were developed to explore the new features, including: (i) both free radical photopolymerization (FRP) efficacy and the production of nanogold (NG), which are proportional to the relative concentration ratios of (A0 + B0 + N0)/G0 and may be optimized for maximum efficacy; (ii) the two competing procedures of NG production and the efficacy of FRP, which can be tailored for an optimal system with nanogold in the polymer matrix; (iii) the FRP efficacy, which is contributed by three components given by the excited state of copper complex (T), and the radicals (R and S) produced by iodonium and amine, respectively; (iv) NG production, which is contributed by the coupling of T and radical (S) with gold ion; and (v) NG production, which has a transient state proportional to the light intensity and the concentration ratio A0/G0) + (N0/(K'M0), but also a steady-state independent of the light intensity.

[Analysis of components of proteins from Echinococcus granulosus cyst fluid]

OBJECTIVE

To analyze the components of proteins from Echinococcus granulosus cyst fluid using the shotgun method, and to identify the active components with potential regulatory effects for immune dysregulation diseases.

METHODS

The E. granulosus cyst fluid was collected aseptically from the hepatic cysts of patients with cystic echinococcosis, and characterized by liquid chromatography (LC) tandem mass spectrometry (MS/MS) following digestion with trypsin. The protein data were searched using the software MaxQuant version 1.6.1.0 and the cellular components, molecular functions, and biological processes of the identified proteins were analyzed using the Gene Ontology (GO) method.

RESULTS

The E. granulosus cyst fluid separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) had a relative molecular mass of 25 to 70 kDa. LS-MS/MS analysis identified 37 proteins, including 32 known proteins and 5 unknown proteins. At least 4 proteins were preliminarily found to exhibit potential regulatory effects for immune dysregulation diseases, including antigen B, glutathione-S-transferase (GST), thioredoxin peroxidase (TPX) and malate dehydrogenase (MDH). GO enrichment analysis showed that the identified proteins had 149 molecular functions and were involved in 341 biological processes.

CONCLUSIONS

E. granulosus cyst fluid has a variety of protein components, and four known proteins are preliminarily identified to be associated with immune dysregulation diseases.

[Effect of platelet reactivity on clinical events in patients using bivalirudin in selective percutaneous coronary intervention]

Objective: To investigate the effect of platelet reactivity and other clinical factors on the postoperative 1-year adverse clinical events in patients who underwent selective percutaneous coronary intervention (PCI) anticoagulated with bivalirudin. Methods: This is a multicenter, retrospective and observational study, enrolling 632 patients at high risk of bleeding adjudicated by operators who underwent selective PCI anticoagulated with bivalirudin and had preoperative thrombelastography (TEG) test results in Fuwai Hospital, Northern Theater General Hospital and Xinxiang Central Hospital between January 2017 and August 2018. Platelet reactivity was tested by TEG and adenosine-induced maximal amplitude (MAADP) was recorded. According to MAADP patients were divided into three groups: low on-treatment platelet reactivity (LTPR) group (MAADP<31 mm, n=229), normal on-treatment platelet reactivity (NTPR) group (31 mm≤MAADP≤47 mm, n=207) and high on-treatment platelet reactivity (HTPR) group (MAADP>47 mm, n=196). The endpoints consisted of major adverse cardiovascular and cerebrovascular events (MACCE) and bleeding events. The definition of MACCE was the composite of all-cause mortality, myocardial infarction, intrastent thrombosis, stroke and revascularization. Bleeding events were defined by bleeding academic research consortium (BARC) type 2, 3 and 5 bleeding. Using multivariate Cox regression to analyze the factors of MACCE and bleeding events in patients underwent selective PCI anticoagulated with bivalirudin. Results: A total of 632 patients were finally enrolled in the study with age of (68.3±10.0) years and there were 423 (66.9%) males. All of 632 patients finished one-year follow-up, and 48 (7.6%) patients occurred MACCE and 11 (1.7%) patients occurred bleeding events. There was not statistically significant difference in the incidence of MACCE (8.3% (19/229) vs. 6.3% (13/207) vs.8.2% (16/196), P=0.68) and bleeding events (1.8% (4/229) vs. 2.9% (6/207) vs. 0.5% (1/196), P=0.17) in LTPR, NTPR and HTPR group. Multivariate Cox regression showed that HTPR was not the independent factor of MACCE (HR=1.25, 95%CI 0.67-2.30, P=0.49), and the history of peripheral vessel disease was the independent risk factor of MACCE (HR=2.47, 95%CI 1.19-5.11, P=0.02). LTPR was not the independent factor of bleeding events (HR=1.35, 95%CI 0.39-4.66, P=0.64), and the independent factors of bleeding events were history of peripheral vessel disease (HR=3.95, 95%CI 1.03-15.22, P=0.05) and hemoglobin (HR=0.96, 95%CI 0.93-0.99, P=0.01). Conclusions: In patients undergoing selective PCI anticoagulated with bivalirudin, there is no significant association between platelet reactivity and postoperative 1-year MACCE or bleeding events. History of peripheral vessel disease is an independent risk factor of MACCE, and history of peripheral vessel disease and decreased hemoglobin are independent risk factors of bleeding events.

[Effects of interpregnancy interval on pregnancy outcomes of subsequent pregnancy: a multicenter retrospective study]

Objective: To explore the effects of interpregnancy interval (IPI) on pregnancy outcomes of subsequent pregnancy. Methods: A multicenter retrospective study was conducted in 21 hospitals in China. Information of age, height, pre-pregnancy weight, IPI, history of diseases, complications of pregnancy, gestational age of delivery, delivery mode, and pregnancy outcomes of the participants were collected by consulting medical records of pregnant women who had two consecutive deliveries in the same hospital during 2011 to 2018. The participants were divided into 4 groups according to IPI:<18 months, 18-23 months, 24-59 months and ≥60 months. According to the WHO's recommendation, with the IPI of 24-59 months group as a reference, to the effects of IPI on pregnancy outcomes of subsequent pregnancy were analyzed. Stratified analysis was further carried out based on age, history of gestational diabetes mellitus (GDM), macrosomia, and premature delivery, to explore the differences in the effects of IPI on pregnancy outcomes among women with different characteristics. Results: A total of 8 026 women were included in this study. There were 423, 623, 5 512 and 1 468 participants in <18 months group, 18-23 months group, 24-59 months group and ≥60 months group, respectively. (1) The age, pre-pregnancy body mass index (BMI), history of cesarean section, GDM, gestational hypertension and cesarean section delivery rate of <18 months group, 18-23 months group, 24-59 months group and ≥60 months group were gradually increased, and the differences were statistically significant (P<0.05). (2) After adjusting for potential confounding factors, compared with women in the IPI of 24-59 months group, the risk of premature delivery, premature rupture of membranes, and oligohydramnios were increased by 42% (OR=1.42, 95%CI: 1.07-1.88, P=0.015), 46% (OR=1.46, 95%CI: 1.13-1.88, P=0.004), and 64% (OR=1.64, 95%CI: 1.13-2.38, P=0.009) respectively for women in the IPI≥60 months group. No effects of IPI on other pregnancy outcomes were found in this study (P>0.05). (3) After stratified by age and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months would significantly increase the risk of oligohydramnios for women with advanced age (OR=2.87, 95%CI: 1.41-5.83, P=0.004); and <18 months could increase the risk of premature rupture of membranes for women under the age of 35 (OR=1.59, 95%CI: 1.04-2.43, P=0.032). Both the risk of premature rupture of membranes (OR=1.58, 95%CI: 1.18-2.13, P=0.002) and premature delivery (OR=1.52, 95%CI: 1.07-2.17, P=0.020) were significantly increased in the IPI≥60 months group. After stratified by history of GDM and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months would lead to an increased risk of postpartum hemorrhage for women with a history of GDM (OR=5.34, 95%CI: 1.45-19.70, P=0.012) and an increased risk of premature rupture of membranes for women without a history of GDM (OR=1.44, 95%CI: 1.10-1.90, P=0.009). After stratified by history of macrosomia and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months could increase the proportion of cesarean section for women with a history of macrosomia (OR=4.11, 95%CI: 1.18-14.27, P=0.026) and the risk of premature rupture of membranes for women without a history of macrosomia (OR=1.46, 95%CI: 1.12-1.89, P=0.005). After stratified by history of premature delivery and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months would significantly increase the risk of premature rupture of membranes for women without a history of premature delivery (OR=1.47, 95%CI: 1.13-1.92, P=0.004). Conclusions: Both IPI≥60 months and <18 months would increase the risk of adverse pregnancy outcomes in the subsequent pregnancy. Healthcare education and consultation should be conducted for women of reproductive age to maintain an appropriate IPI when they plan to pregnant again, to reduce the risk of adverse pregnancy outcomes in the subsequent pregnancy.

[Five-year clinical outcomes of the second generation biodegradable polymer sirolimus-eluting stent (EXCROSSAL) in treating patients with de novo coronary lesions]

Objective: To evaluate the five-year safety and efficacy of the second generation biodegradable polymer sirolimus-eluting stent (EXCROSSAL) in treating patients with de novo coronary artery diseases. Methods: Patients with coronary artery disease (CAD)who were implanted with EXTROSSAL stents in CREDIT Ⅱ and CREDIT Ⅲ study were included. CREDIT Ⅱ was a randomized trial, and CREDIT Ⅲ was a single-arm study. From November 2013 to December 2014, 833 CAD patients with de novo coronary lesions implanted with EXTROSSAL stents were selected from 33 centers in China. The primary outcome was 5-year target lesion failure (TLF), a composite of cardiac death, target vessel myocardial infarction and clinically indicated target lesion revascularization. Secondary endpoints was patient-oriented composite endpoint (PoCE), including all-cause death, all myocardial infarction, or any revascularization within 5 years post stenting and stent thrombosis according to Academic Research Consortium's (ARC) definition. Kaplan Meier method was used to calculate the incidence of TLF and PoCE within 5 years after operation. Univariate Cox regression analysis was used to analyze the impacts of diabetes, small vessel disease (vessel diameter ≤ 2.74 mm), lesion length ≥ 16.7 mm and multivessel disease on the incidence of TLF within 5 years after operation. Results: A total of 833 patients were included in this study including 579 males (69.5%), the age was (59.3±9.1) years. And 832 (99.9%) patients completed 5-year clinical follow-up. The incidence of TLF and PoCE in the 5-year follow-up were 10.6%(86/811) and 15.5%(126/811), respectively. Stent thrombosis occurred in 1.0%(8/811) of patients. Univariate Cox regression analysis showed that vessel diameter ≤ 2.74 mm (HR=3.20,95%CI 1.90-5.39,P<0.001), lesion length ≥ 16.7 mm (HR=1.88,95%CI 1.18-2.99,P=0.007) and multivessel disease (HR=2.44,95%CI 1.60-3.72,P<0.001) were related factors of TLF within 5 years after operation. Conclusion: EXCROSSAL stent is effective and safe in treating CAD patients with de novo coronary lesions, with low incidence of TLF and PoCE within 5 years after operation.

[A pathological report of three COVID-19 cases by minimal invasive autopsies]

Objective: To investigate the pathological characteristics and the clinical significance of novel coronavirus (2019-nCoV)-infected pneumonia (termed by WHO as coronavirus disease 2019, COVID-19). Methods: Minimally invasive autopsies from lung, heart, kidney, spleen, bone marrow, liver, pancreas, stomach, intestine, thyroid and skin were performed on three patients died of novel coronavirus pneumonia in Chongqing, China. Hematoxylin and eosin staining (HE), transmission electron microcopy, and histochemical staining were performed to investigate the pathological changes of indicated organs or tissues. Immunohistochemical staining was conducted to evaluate the infiltration of immune cells as well as the expression of 2019-nCoV proteins. Real time PCR was carried out to detect the RNA of 2019-nCoV. Results: Various damages were observed in the alveolar structure, with minor serous exudation and fibrin exudation. Hyaline membrane formation was observed in some alveoli. The infiltrated immune cells in alveoli were majorly macrophages and monocytes. Moderate multinucleated giant cells, minimal lymphocytes, eosinophils and neutrophils were also observed. Most of infiltrated lymphocytes were CD4-positive T cells. Significant proliferation of type Ⅱ alveolar epithelia and focal desquamation of alveolar epithelia were also indicated. The blood vessels of alveolar septum were congested, edematous and widened, with modest infiltration of monocytes and lymphocytes. Hyaline thrombi were found in a minority of microvessels. Focal hemorrhage in lung tissue, organization of exudates in some alveolar cavities, and pulmonary interstitial fibrosis were observed. Part of the bronchial epithelia were exfoliated. Coronavirus particles in bronchial mucosal epithelia and type Ⅱ alveolar epithelia were observed under electron microscope. Immunohistochemical staining showed that part of the alveolar epithelia and macrophages were positive for 2019-nCoV antigen. Real time PCR analyses identified positive signals for 2019-nCoV nucleic acid. Decreased numbers of lymphocyte, cell degeneration and necrosis were observed in spleen. Furthermore, degeneration and necrosis of parenchymal cells, formation of hyaline thrombus in small vessels, and pathological changes of chronic diseases were observed in other organs and tissues, while no evidence of coronavirus infection was observed in these organs. Conclusions: The lungs from novel coronavirus pneumonia patients manifest significant pathological lesions, including the alveolar exudative inflammation and interstitial inflammation, alveolar epithelium proliferation and hyaline membrane formation. While the 2019-nCoV is mainly distributed in lung, the infection also involves in the damages of heart, vessels, liver, kidney and other organs. Further studies are warranted to investigate the mechanism underlying pathological changes of this disease.

Thermo-responsive hydrogel as an anti-VEGF drug delivery system to inhibit retinal angiogenesis in Rex rabbits

BACKGROUND

Wet age-related macular degeneration (Wet AMD) has been treated clinically by intravitreal injection of bevacizumab, which is a kind of the anti-VEGF antibody drug. Nevertheless, because of the short half-life and frequent injections, the use of this treatment is limited.

OBJECTIVE

To confirm whether mPEG-PLGA-BOX can be considered as a VEGF drug delivery system to inhibit retinal angiogenesis.

METHODS

A thermo-responsive hydrogel of methoxy-poly (ethylene glycol)-block-poly (lactic-co-glycolic acid) (mPEG-PLGA-BOX) was synthesized. The thermo-responsive hydrogel mPEG-PLGA-BOX was able to have sol-gel phase transition upon stimulation by the body temperature with improved biocompatibility and biodegradation. The bevacizumab released from mPEG-PLGA-BOX inhibited RF/6A cells according to a JC-1 assay, which indicated that the released bevacizumab was active to be able to suppress the growth of new blood vessels. In an animal study, retinal laser photocoagulation was performed to induce angiogenesis in the eyes of Rex rabbits using an 810-mm laser.

RESULTS

The retina was penetrated when the laser power was more than 500 mW and the exposure time was more than 500 ms. New blood vessels were created at the 28th day after retinal laser photocoagulation. At this time, intravitreal 0.05-mL injections of mPEG-PLGA-BOX (bevacizumab) solution were administered. The bevacizumab released from mPEG-PLGA-BOX (bevacizumab) solution suppressed the angiogenesis. In an in vivo study, the histomorphology of the rabbit retina also indicated that mPEG-PLGA-BOX after intravitreal injection is not toxic to the rabbit retina.

CONCLUSIONS

Bevacizumab released from mPEG-PLGA-BOX (bevacizumab) solution suppressed angiogenesis, and mPEG-PLGA-BOX can be considered as a novel thermo-responsive hydrogel with potential as a gelling carrier for extended bevacizumab drug release to treat intraocular neovascular diseases.

Effects of thermal boundary condition on methane oxidation in landfill cover soil at different ambient temperatures

Microbial aerobic methane oxidation (MAMO) has been considered as an environmental-friendly method for mitigating methane emission from municipal landfill sites. Soil column has in a landfill cover under one-dimensional (1-D) condition. However, most of the published soil column tests failed to simulate 1-D heat transfer due to the use of thermal conductive boundary at the sidewall. In the present study, a heavily instrumented soil column was developed to quantify the effects of thermal boundary condition on the methane oxidation efficiency under different ambient temperatures in landfill cover soil. The sidewall of the soil column was thermally insulated to ensure 1-D heat transport as would have been typically expected in the field condition. Two soil column tests with and without thermal insulation were conducted at a range of controlled ambient temperatures from 15 to 30°C, for studying how soil moisture, matric suction, gas pressure, soil temperature and gas concentration evolve with MAMO. The test results reveal that ignoring thermal insulation in a soil column test would result in a greater loss of soil heat generation by MAMO and hence oxidation efficiency by up to 100% for the range of temperature considered. When the ambient temperature increased to 30°C (but less than the optimum temperature for MAMO), the MAMO efficiency increased abruptly at first but then decreased substantially with time, and this is likely due to the accumulation of biomass generated by MAMO.

Modeling the Kinetics, Curing Depth, and Efficacy of Radical-Mediated Photopolymerization: The Role of Oxygen Inhibition, Viscosity, and Dynamic Light Intensity

Kinetic equations for a modeling system with type-I radical-mediated and type-II oxygen-mediated pathways are derived and numerically solved for the photopolymerization efficacy and curing depth, under the quasi-steady state assumption, and bimolecular termination. We show that photopolymerization efficacy is an increasing function of photosensitizer (PS) concentration (C ₀) and the light dose at transient state, but it is a decreasing function of the light intensity, scaled by [C ₀/I ₀]^0.5 at steady state. The curing (or cross-link) depth is an increasing function of C ₀ and light dose (time × intensity), but it is a decreasing function of the oxygen concentration, viscosity effect, and oxygen external supply rate. Higher intensity results in a faster depletion of PS and oxygen. For optically thick polymers (>100 um), light intensity is an increasing function of time due to PS depletion, which cannot be neglected. With oxygen inhibition effect, the efficacy temporal profile has an induction time defined by the oxygen depletion rate. Efficacy is also an increasing function of the effective rate constant, K = k'/ k T 0 . 5 , defined by the radical producing rate (k') and the bimolecular termination rate (k _T). In conclusion, the curing depth has a non-linear dependence on the PS concentration, light intensity, and dose and a decreasing function of the oxygen inhibition effect. Efficacy is scaled by [C ₀/I ₀]^0.5 at steady state. Analytic formulas for the efficacy and curing depth are derived, for the first time, and utilized to analyze the measured pillar height in microfabrication. Finally, various strategies for improved efficacy and curing depth are discussed.

Dual-Wavelength (UV and Blue) Controlled Photopolymerization Confinement for 3D-Printing: Modeling and Analysis of Measurements

The kinetics and modeling of dual-wavelength (UV and blue) controlled photopolymerization confinement (PC) are presented and measured data are analyzed by analytic formulas and numerical data. The UV-light initiated inhibition effect is strongly monomer-dependent due to different C=C bond rate constants and conversion efficacies. Without the UV-light, for a given blue-light intensity, higher initiator concentration (C10) and rate constant (k') lead to higher conversion, as also predicted by analytic formulas, in which the total conversion rate (RT) is an increasing function of C1 and k'R, which is proportional to k'[gB1C1]0.5. However, the coupling factor B1 plays a different role that higher B1 leads to higher conversion only in the transient regime; whereas higher B1 leads to lower steady-state conversion. For a fixed initiator concentration C10, higher inhibitor concentration (C20) leads to lower conversion due to a stronger inhibition effect. However, same conversion reduction was found for the same H-factor defined by H0 = [b1C10 - b2C20]. Conversion of blue-only are much higher than that of UV-only and UV-blue combined, in which high C20 results a strong reduction of blue-only-conversion, such that the UV-light serves as the turn-off (trigger) mechanism for the purpose of spatial confirmation within the overlap area of UV and blue light. For example, UV-light controlled methacrylate conversion of a glycidyl dimethacrylate resin is formulated with a tertiary amine co-initiator, and butyl nitrite. The system is subject to a continuous exposure of a blue light, but an on-off exposure of a UV-light. Finally, we developed a theoretical new finding for the criterion of a good material/candidate governed by a double ratio of light-intensity and concentration, [I20C20]/[I10C10].

[Long-term efficacy of a second generation biodegradable polymer sirolimus-eluting stent (EXCEL2) in treating patients with de novo coronary artery diseases]

Objective: To evaluate the long-term efficacy of a second generation biodegradable polymer sirolimus-eluting stent (EXCEL2) in treating patients with de novo coronary artery diseases. Methods: CREDIT Ⅱ trial was a prospective, multicenter, randomized, controlled study, conducted at 15 Chinese cardiac centres from November 2013 to December 2014. In this analysis, eligible patients for coronary stenting (n=419) were randomized to receive either the EXCEL2 stent (n=208) or the EXCEL stent (n=211). The primary endpoint was target lesion failure (TLF) at 3 years after PCI defined as a composite endpoints of cardiac death, target vessel myocardial infarction (TVMI), or clinically indicated target lesion revascularization (CI-TLR). Secondary endpoints included patient-oriented composite endpoint (PoCE) including all-cause death, all MI, or any revascularization at 3 years and independent components, and stent thrombosis according to Academic Research Consortium's (ARC) definition. Results: Among 419 enrolled patients, 413 (98.6%) patients completed 3-year clinical follow-up. Compared with the EXCEL group, 3-year TLF (5.4%(11/204) vs. 11.5% (24/209), P=0.025) and PoCE (9.8% (20/204) vs. 20.1% (42/209), P=0.003) were significantly lower in the EXCEL2 group. The cumulative event rate of CI-TLR (2.0% (4/204) vs. 5.7% (12/209), P=0.042) and any revascularization (4.9% (10/204) vs. 14.4% (30/209), P=0.001) were statistically lower in the EXCEL2 group than in the EXCEL group. There were no significant difference between two groups in terms of all-cause death and all MI. Rates of stent thrombosis were low without significant difference between the two groups (EXCEL2 vs. EXCEL, 1.0% (2/204) vs. 2.9% (6/209), P=0.285). Conclusion: 3-year clinical follow-up results demonstrate that EXCEL2 stents are effective and safe in treating CAD patients with de novo coronary lesions.

[The value of red blood cell distribution width in the evaluation of patients with obstructive sleep apnea hypopnea syndrome]

Objective:To investigate the relationship between red blood cell distribution width (RDW) and severity of obstructive sleep apnea hypopnea syndrome (OSAHS). Method:A total of 112 patients with OSAHS who were diagnosed by PSG monitoring were selected as OSAHS group, and 61 healthy subjects with matched age, gender and BMI were selected as the control group. The peripheral venous blood of all subjects was collected in the morning, and relevant hematological indexes such as RDW, white blood cell count, red blood cell count, hemoglobin, mean red blood cell volume, and platelet count were obtained. Result:The RDW level in the OSAHS group was significantly higher than that in the control group. The RDW value increased gradually with the severity of OSAHS and was positively correlated with AHI(r=0.259), the mean SaO₂ (r=-0.279), the lowest SaO₂( r=-0.328), BMI(r=0.203) and negatively correlated with sleep time(r=-0.204). Conclusion:The elevated level of RDW may be an indicator of the severity of OSAHS. Since RDW is usually included in the complete blood count, it can provide an economical and practical indicator to initially assess the condition of OSAHS patients and prioritize polysomnography monitoring.

Effects of chlorogenic acid-enriched extract from Eucommia ulmoides leaf on performance, meat quality, oxidative stability, and fatty acid profile of meat in heat-stressed broilers

To investigate the effects of chlorogenic acid-enriched extract (CGAE) from Eucommia ulmoides leaf on performance, meat quality, oxidative stability, and fatty acid profile of breast meat in heat-stressed broilers, 400 28-day-old male Ross 308 broilers were randomly assigned into 4 groups with 10 replicates per group (10 broilers per replicate). Broilers in the normal group (NOR) were kept at 22 ± 2°C (24 h/D) and fed the basal diet, and the other 3 groups were treated with cyclic heat (34 ± 2°C from 08:00 to 18:00 and 22 ± 2°C from 18:00 to 08:00) and fed the basal diet supplemented with 0 (HT), 500 (CGAE500), and 1,000 mg (CGAE1000) mg of CGAE/kg of diet. The experiment lasted for 14 D. Compared with the HT group, broilers in the NOR and CGAE1000 groups had a higher average daily gain and a lower feed conversion ratio (P < 0.05). CGAE supplementation at 1,000 mg/kg increased pH24 value, a* value and total superoxide dismutase activity and reduced drip loss, cooking loss, L* value and the contents of malondialdehyde and carbonyl in breast meat of heat-stressed broilers (P < 0.05). Broilers in the HT group showed lower mRNA levels of nuclear factor erythroid 2-related factor 2 (P < 0.001), superoxide dismutase (P = 0.004), and catalase (P < 0.001) in breast meat compared with the other groups. CGAE supplementation at 1,000 mg/kg reduced the stearic acid and saturated fatty acids (SFA) contents and increased the dihomo-γ-linolenic acid, linoleic acid, linolenic acid, eicosapentaenoic acid, polyunsaturated fatty acids (PUFA), and n-6 PUFA contents and PUFA:SFA ratio in breast meat of heat-stressed broilers (P < 0.05). In conclusion, CGAE supplementation at 1,000 mg/kg could alleviate the adverse effects of heat stress on growth performance and meat quality and improve oxidative stability and fatty acid profile of breast meat in heat-stressed broilers.

Antimicrobial resistance and virulence genes of Streptococcus isolated from dairy cows with mastitis in China

Streptococcus is a major mastitis-causing pathogen in dairy cows. To investigate the prevalence, antimicrobial resistance and virulence gene of Streptococcus in mastitic milk, a total of 735 mastitic raw milk samples from dairy cows in 11 provinces of China were collected and tested. Antimicrobial resistance of Streptococcus isolates was determined by disc diffusion against 8 classes 29 antimicrobial agents, and Streptococcus resistant genes and virulence genes were determined by PCR and agarose gel electrophoresis. A total of 64 (8.71%) isolates of Streptococcus were isolated and identified using biochemical profiling, including 22 isolates of Streptococcus agalactiae, 13 isolates of Streptococcus dysgalactiae, and 29 isolates of Streptococcus uberis. Out of 64 resistant Streptococcus isolates, all isolates (100%) were resistant to 3 or more antimicrobials. The most frequency (n = 18, 28.12%) of the isolates were multi-resistant to 5-7 antimicrobials and the highest multi-resistant number was 29 (n = 1, 1.56%). Streptococcus isolates had the highest resistance rate to tetracycline (98.44%) and oxacillin (98.44%), followed by penicillin G (96.88%) and doxycycline (96.88%), and the lowest resistance was observed with respect to ciprofloxacin (1.56%). A total of 16 antimicrobials resistance genes with 25 combination patterns were detected in the isolates. The gene combination of Sul1/Sul2/Sul3 + gyrA/parC + cat1/cat2 was the most common pattern (12.5%). The correlation between resistant phenotypes and resistance genes in Streptococcs was 35.87%. A total of 7 virulence genes were detected and 59 (92.19%) isolates harbored at least one gene. Twenty-four classes of gene patterns were found in the isolates and the patterns of bca (9.38%) and cfb (9.38%) were the most prevalent form. In conclusion, the issue of drug resistance of Streptococcus is still a great concern in cattle health in China.

[The clinical characteristics and two different treatment outcomes of 321 patients with hypopharyngeal squamous cell carcinoma]

Objective:To investigate the clinical characteristics, two different treatment outcomes and prognostic factors of hypopharyngeal carcinoma. Method:The life table method was used to calculate the overall survival rates, Log-rank test was used to compare the overall survival rates between the two groups．The Cox proportional hazard model was used to perform the multivariate analysis to confirm independent treatment modalities as prognostic factors. Result:Among the 321 patients, 197 patients received surgery combine with radiotherapy or concurrent chemoradiotherapy treatment（S+R/CRT） and 124 patients received radiotherapy or concurrent chemoradiotherapy treatment(R/CRT). For 321 patients, the 1,3,5year overall survival rates were 75.87%,49.39%,41.38% and the median survival time was 37.65 months. The difference in throat retention ratio between the radiotherapy or concurrent chemoradiotherapy treatment(41.94%) and surgery combine with radiotherapy or concurrent chemoradiotherapy treatment（11.17%) was statistically significant (P<0.01).Univariate analysis showed that clinical stage of tumor, T stage, N stage, M stage and two different treatment modalities have impact on survival prognosis. Cox regression multivariate analysis showed that T stage, N stage, two different treatment modalities were independent risk factors of prognosis. Conclusion:The overall prognosis of hypopharyngeal carcinoma was poor and dismal. Hypopharyngeal carcinoma is characterized by high degree of malignancy, difficult to be found early, prone to recurrence and metastasis after operation, large trauma and poor prognosis. Comprehensive examination should be conducted to define the stage of tumor and choose the rational treatment plan before treatment. Surgery combine with radiotherapy or chemotherapy treatment modality is still the main treatment strategy for advanced-stage hypopharyngeal carcinoma..

[An experimental study of CD4 targeted chimeric antigen receptor modified T cell with anti-lymphoma activity]

目的

探讨针对CD4膜蛋白的CAR-T细胞对CD4⁺T细胞淋巴瘤细胞的靶向特异性杀伤作用。

方法

采用重组DNA技术构建含4-1BB共刺激分子的第二代针对CD4的CAR慢病毒载体，应用293T细胞包装慢病毒，采用流式细胞术检测T细胞的转染效率及T细胞亚群动态变化，采用流式细胞术微球法检测培养上清中IFN-γ浓度。

结果

①构建的慢病毒载体转染激活的T细胞后CAR膜蛋白阳性率达到50.0%~70.0%。T细胞激活后部分CD8⁺T细胞弱表达（dim）CD4膜蛋白。T细胞转染针对CD4的CAR慢病毒后CD4⁺ T细胞、CD8⁺ CD4^dim T细胞逐渐被清除。②CAR-T细胞、对照组T细胞（空载体转染的T细胞）以8∶1效靶比分别与CD4⁺人T细胞淋巴瘤细胞株KARPAS 299细胞共培养24 h，杀伤效率分别为（96.9±2.1）%和（11.2±3.1）%，前者明显高于后者（t=7.137，P=0.028）。③CAR-T细胞单独培养，与转染慢病毒载体表达人CD4的K562细胞（K562-CD4细胞）、K562细胞共培养后上清中IFN-γ浓度分别为（1 785±268）、（15 648±2 168）、（1 978±354）pg/ml，CAR-T细胞与K562-CD4细胞共培养上清IFN-γ浓度明显高于其他两组，差异有统计学意义（P<0.01）。

结论

CD4特异性CAR-T细胞效应细胞免疫表型为CD8⁺ CD4⁺ T细胞，在体外具有杀伤正常CD4⁺ T细胞和CD4⁺ T细胞淋巴瘤细胞的活性，对于CD4^dim T细胞也有较好的清除活性。