[Application of the small private online course-based blended teaching model in Human Parasitology teaching]

Small private online course (SPOC), an emerging network-based, student-centered blended teaching model, combines the advantages of online teaching and flipped classroom, aiming to effectively improve students' autonomous learning ability and learning efficiency. Considering a remarkable decline in the course of Human Parasitology, we built an SPOC-based blended teaching model for Human Parasitology, covering pre-course learning, intra-course leaning, post-course consolidation and evaluation, and such a model was applied among grade 2019 students with specialty of clinical medicine. Following the application of the SPOC-based blended teaching model, most students had improvements in autonomous learning ability and activity, and understanding of human parasitology knowledge, and the examination score disparity was avoided.

[Observation of effective dosage of remimazolam tosilate used for moderate-to-deep sedation in fiberoptic bronchoscopy]

Objective: To estimate the safety and efficacy of remimazolam tosilate used for moderate-to-deep sedation in fiberoptic bronchoscopy with its 50% effective dosage (ED50) and 95% effective dosage (ED95) calculated. Methods: A total of 50 patients aged from 18 to 65 years and classified as Class Ⅰ or Ⅱ according to the American Society of Anesthesiologists (ASA) Classification who underwent fiberoptic bronchoscopy in Hainan Cancer Hospital from April to August of 2020 were included in this study. For each patient, bronchoscopy was only started when the eyelash reflex disappeared and MOAA/S score was<1 after a trial dose of remimazolam tosilate combined with 0.1 μg/kg sufentanil was intravenously given. The dosage of remimazolam tosilate for the first patient was 0.18 mg/kg, based on which the dosages for the following patients were increased or decreased by 1∶1 times for one another, forming an equal ratio sequence. A maintenance dose of remimazolam tosilate was pumped intravenously in a rate of 1 mg/(kg·h) during the bronchoscopic examination and treatment. The result of the sequential trial, the time to achieve proper sedation, the analepsia time and the adverse effects were recorded. Results: All the 50 patients went through bronchoscopy completely. The regression function of the sequential trial was Y=12.589+16.593X, the ED50 and the ED95 of remimazolam tosilate were 0.174 (95%CI: 0.162-0.186) mg/kg and 0.219 (95%CI: 0.199-0.312) mg/kg, respectively. The time to achieve proper sedation was (50±11) s and the mean analepsia time after the use of flumazenil was (56±16) s. There was one patient with respiratory inhibition, one with headache and dizziness, one with fatigue among the 50 patients. Conclusions: The strategy of moderate-to-deep sedation based on remimazolam tosilate is safe and effective in bronchoscopic examination and treatment. When combined with 0.1 μg/kg sufentanil, the ED50 and the ED95 of remimazolam tosilate are 0.174 mg/kg and 0.219 mg/kg, respectively.

Echocardiography update for primary care physicians: a review

Echocardiography is a key evaluation tool for the diagnosis, prognosis, and guidance of interventional management of numerous cardiovascular conditions, including ischaemia, heart failure, and structural heart diseases. Recent technological advancements have also seen the exploration of artificial intelligence, intracardiac vortex imaging, and three-dimensional printing in echocardiography. With cardiovascular diseases increasing in prevalence worldwide, it is important for clinicians including general practitioners to have updated knowledge of appropriate use of echocardiography. As such, this article reviews the current literature and summarises the latest developments and the general clinical usage of echocardiography.

P1822Pocket-size mobile echocardiographic device screening for thoracic aortic aneurysm in asymptomatic hypertensive patients

Background

Patients with hypertension may develop thoracic aortic aneurysm (TAA) that can be asymptomatic but potentially life-threatening. We sought to assess the prevalence of asymptomatic TAA among hypertensive patients and define the effectiveness of a TAA point-of-care screening program using pocket-size mobile echocardiographic (PME) devices.

Methods

We prospectively performed transthoracic echocardiography for TAA screening using a PME device on 1529 hypertensive patients (age, 62y [30y to 85y], 824 men) who attended our hypertension specialist clinic between June 2016 and July 2018. Measurement of the dimensions of the aortic sinus, sinotubular junction, ascending aorta, aortic arch, and descending thoracic aorta were obtained through multiple standard echo views.

Results

The prevalence of TAA (defined as maximum aortic diameter of ≥4.5cm and/or >50% diameter of the adjacent aorta) in our study population was 7.3% (111/1529), with distal ascending aorta as the most frequent location (Figure). Multiple logistic regression analysis identified male gender, older age, and presence of heart valve disease as independent factors associated with TAA (all p<0.05).

Figure 1

Conclusions

Asymptomatic TAA is common among asymptomatic hypertensive patients. Point-of-care use of PME device is effective in detecting TAA in a clinic setting. Such approach may be useful for early detection of TAA among at-risk patients allowing aggressive blood pressure control and early surgical intervention to prevent catastrophic complications such as aortic dissection or rupture.

Acknowledgement/Funding

Health and Medical Research Fund of the Hong Kong Government

Direct degradation of cellulosic biomass to bio-hydrogen from a newly isolated strain Clostridium sartagoforme FZ11

A mesophilic hydrogen-producing strain, Clostridium sartagoforme FZ11, had been newly isolated from cow dung compost acclimated using microcrystalline cellulose (MCC) for at least 30 rounds in an anaerobic bioreactor, and identified by the 16S rDNA gene sequencing, which could directly utilized various carbon sources, especially cellulosic biomass, to produce hydrogen. The maximum hydrogen yields from MCC (10 g/l) and carboxymethyl cellulose (CMC, 10 g/l) were 77.2 and 64.6 ml/g, separately. Furthermore, some key parameters of affecting hydrogen production from raw corn stalk were also optimized. The maximal hydrogen yield and substrate degradation rate from raw corn stalk were 87.2 ml/g and 41.2% under the optimized conditions with substrate concentration of 15 g/l, phosphate buffer of 0.15 M, urea of 6 g/l and initial pH of 6.47 at 35 °C. The result showed that the strain FZ11 would be an ideal candidate to directly convert cellulosic biomass into bio-hydrogen without substrate pretreatment.

Photocatalytic hydrogen evolution from a cobalt/nickel complex with dithiolene ligands under irradiation with visible light

Novel cobalt/nickel dithiolene complexes displayed efficient hydrogen evolution in a noble-metal-free photocatalytic system under visible light.

Direct bioconversion of raw corn stalk to hydrogen by a new strain Clostridium sp. FS3

A new strain FS3 which could achieve an efficient bioconversion of raw corn stalk to hydrogen had been isolated from anaerobic acclimated sludge, and identified as Clostridium butyricum on the basis of a series of physiological and biochemical experiments and 16S rDNA gene sequence. The strain could utilize various carbon sources to produce hydrogen. On the basis of single-factor experiments, the response surface methodology (RSM) was performed to optimize the media for hydrogen production. The maximum hydrogen yield of 92.9ml/g was observed under the optimal conditions: 20g/l raw corn stalk, 1.76g/l NH4HCO3, 0.91g/l KH2PO4 and 10.4ml/l nutrient solution. This finding opens a new avenue for direct conversion of raw cellulosic biomass to bio-hydrogen.

Photocatalytic H2 generation based on noble-metal-free binuclear cobalt complexes using visible-light

Two new binuclear cobalt complexes, namely {[Co(dmgH)(dmgH2)]2L1} (I) and {[Co(dmgH)(dmgH2)]2L2} (II) (dmgH = dimethylglyoximate monoanion; dmgH2 = dimethylglyoxime, L1 = 1,3-bis(4-pyridyl)propane), L2 = 1,3-bis(imidazol-1-ylmethyl)benzene), have been synthesized by the self-assembly of [Co(dmgH)(dmgH2)] and L1 or L2, respectively. An efficient photocatalytic system was constructed by combining a noble-metal-free cobalt complex as the catalyst with Eosin Y dye (EY(2-)) as the photosensitizer to give an efficient H2 generating system under visible-light irradiation (λ > 420 nm) using triethanolamine (TEOA) as a sacrificial electron donor. The maximum amount of H2 generated was 1013 TON for I and 1134 TON for II over a 2 h irradiation period (λ > 420 nm) under the conditions of pH 8.0, 5% TEOA (v/v), an EY(2-) concentration of 4.0 × 10(-4) M and a catalyst concentration of 4.0 × 10(-4) M in the mixed solvent system of CH3CN-H2O (3 : 1, v/v). In addition, the mechanism of H2 generation in the photolysis system was briefly discussed.

Statistical optimization of process parameters on biohydrogen production from glucose by Clostridium sp. Fanp2

Statistically based experimental designs were applied to optimizing process parameters for hydrogen production from glucose by Clostridium sp. Fanp2 which was isolated from effluent sludge of anaerobic hydrogen-producing bioreactor. The important factors influencing hydrogen production, which identified by initial screening method of Plackett-Burman, were glucose, phosphate buffer and vitamin solution. The path of steepest ascent was undertaken to approach the optimal region of the three significant factors. Box-Behnken design and response surface analysis were adopted to further investigate the mutual interaction between the variables and identify optimal values that bring maximum hydrogen production. Experimental results showed that glucose, vitamin solution and phosphate buffer concentration all had an individual significant influence on the specific hydrogen production potential (Ps). Simultaneously, glucose and vitamin solution, glucose and phosphate buffer were interdependent. The optimal conditions for the maximal Ps were: glucose 23.75 g/l, phosphate buffer 0.159 M and vitamin solution 13.3 ml/l. Using this statistical optimization method, the hydrogen production from glucose was increased from 2248.5 to 4165.9 ml H2/l.

[Enlargement test studies of bio-hydrogen production using artificial wastewater of corn stalk fermentation lixivium by mixed culture]

Conversion of artificial corn stalk wastewater, which was prepared according to the main composition of the corn stalk fermentation lixivium, into bio-hydrogen gas by mixed culture was performed in a 20 L half-continuous flow fermenter. The influences of several environmental factors on the bio-hydrogen production, such as HRT, C/N ratio, Fe2+ and artificial corn stalk wastewater concentration were discussed in the tests. The experimental results showed that HRT, C/N ratio, Fe2+ and artificial corn stalk wastewater concentration significantly affected the fermentation hydrogen production. The maximum H2 yield of 11.80 mol/kg, H2 concentration of 56% and hydrogen production rate of 8.81 L/(L x d) were obtained at HRT = 10 h, C/N = 100, Fe2+ concentration of 100 mg/L and substrate concentration of 12.5 g/L by mixed culture, respectively. In the fermentation hydrogen-producing process, the conversion efficiency of the substrate was more than 90%, and 39.40% of COD was removed from the reactor. The main by-products in the liquid phase were acetic acid, butyric acid, propionic acid and a little ethanol and butanol throughout this study.

Efficient conversion of wheat straw wastes into biohydrogen gas by cow dung compost

Efficient conversion of wheat straw wastes into biohydrogen gas by cow dung compost was reported for the first time. Batch tests were carried out to analyze influences of several environmental factors on biohydrogen production from wheat straw wastes. The performance of biohydrogen production using the raw wheat straw and HCl pretreated wheat straw was then compared in batch fermentation tests. The maximum cumulative hydrogen yield of 68.1 ml H2/g TVS was observed at 126.5 h, the value is about 136-fold as compared with that of raw wheat straw wastes. The maximum hydrogen production rate of 10.14 ml H2/g TVS h was obtained by a modified Gompertz equation. The hydrogen content in the biogas was 52.0% and there was no significant methane observed in this study. In addition, biodegradation characteristics of the substrate were also discussed. The experimental results showed that the pretreatment of the substrate plays a key role in the conversion of the wheat straw wastes into biohydrogen by the composts generating hydrogen.

Testing candidate genes for non-syndromic oral clefts using a case-parent trio design

Markers in five candidate genes were examined on 269 case-parent trios ascertained through a child with an isolated, non-syndromic oral cleft (cleft lip, CL; cleft palate, CP; or cleft lip and palate, CLP). Cases and their parents were ascertained through treatment centers in Maryland. Markers at two of the five candidate genes, transforming growth factor beta3 (TGFbeta3) and MSX1, showed consistent evidence of linkage and disequilibrium due to linkage using several statistical tests (e.g., the global chi-square for TGFbeta3 was 21.1 with 12 df, P = 0.03; that for MSX1 was 8.7 with 3 df, P = 0.03). There was little evidence of heterogeneity in the role of TGFbeta3 between different types of oral clefts, but MSX1 did yield marginal evidence for such heterogeneity. MSX1 also showed evidence for interaction between infant's genotype and maternal smoking, giving a likelihood ratio test for heterogeneity between smoker and non-smoker mothers of 7.16 (2 df, P = 0.03). Using a conditional logistic model to test for gene-gene interaction showed no evidence of interaction between TGFbeta3 and MSX1, with both seeming to contribute independently to risk of isolated, non-syndromic oral clefts.

A case-control study of nonsyndromic oral clefts in Maryland

PURPOSE

Isolated, nonsyndromic oral clefts cases (n = 171) and unaffected controls (n = 182) were used to identify both genetic and environmental risk factors.

METHODS

Infants born in Maryland between 1992 to 1998 with an isolated, nonsyndromic oral cleft [cleft lip (CL), cleft lip and palate (CLP), or cleft palate (CP)] were recruited and exposure plus family history data were collected. Controls were unaffected infants. DNA was collected from all cases and their parents, plus controls.

RESULTS

No statistically significant association was found between any of the following: maternal smoking, vitamin use, urinary tract infection, or recreational drug use in either univariate analysis or after adjusting for maternal age and education. More control mothers reported alcohol use during the critical time period of pregnancy (one month before conception through the first trimester) as compared to case mothers. There was a 10-fold increase in risk to siblings of cases as compared to siblings of controls. Markers at four candidate genes were examined: transforming growth factor alpha (TGF alpha), transforming growth factor beta 3 (TGF beta 3), MSX1, and BCL3. Only MSX1 showed significant differences in allele frequencies between CP cases and controls. MSX1 also showed significant evidence of linkage disequilibrium with a susceptibility gene controlling risk for CP.

CONCLUSION

Most environmental risk factors examined here gave little evidence of association with risk to isolated, nonsyndromic oral clefts, although any alcohol consumption seemed protective. MSX1 showed evidence of linkage disequilibrium in both case-control and case-parent trio analysis.

Application of the surface rendering technique of three-dimensional ultrasound in prenatal diagnosis and counselling of Klippel-Trenaunay-Weber syndrome

Klippel Trenaunay-Weber syndrome is a complex developmental disorder characterized by a triad of cutaneous haemangioma, varicosities of the body, and unilateral limb hypertrophy. We describe the prenatal diagnosis of Klippel-Trenaunay-Weber syndrome at 15 weeks' gestation using the surface rendering technique of three-dimensional ultrasound. The vivid three-dimensional images of the affected fetus are invaluable in prenatal diagnosis and parental counselling.