Comorbid Diabetes Mellitus was Associated with Poorer Prognosis in Patients with COVID-19: A Retrospective Cohort Study

BackgroundThe 2019 novel coronavirus disease (COVID-19) emerged in Wuhan, Hubei province, China, and was characterized as pandemic by the World Health Organization. Diabetes mellitus is an established risk factor for poor clinical outcomes, but the association of diabetes with the prognosis of COVID-19 have not been reported yet. MethodsIn this cohort study, we retrospectively reviewed 258 consecutive hospitalized COVID-19 patients with or without diabetes at the West Court of Union Hospital of Huazhong University of Science and Technology in Wuhan, China, recruited from January 29 to February 12, 2020. The cases were confirmed by real-time PCR and the demographic, clinical, laboratory, radiological, and treatment data were collected and analyzed. Prognosis was defined as hospitalization, discharged survivor and death, which was followed up until March 12, 2020. ResultsOf the 258 hospitalized patients (63 with diabetes) with COVID-19, the median age was 64 years (range 23-91), and 138 (53.5%) were male. No significant differences in age and sex were identified between patients with and without diabetes. Common symptoms included fever (82.2%), dry cough (67.1%), polypnea (48.1%), and fatigue (38%). Patients with diabetes had significantly higher leucocyte and neutrophil counts, and higher levels of fasting blood glucose, serum creatinine, urea nitrogen and creatine kinase isoenzyme MB at admission compared with those without diabetes. COVID-19 patients with diabetes were more likely to develop severe or critical disease condition with more complications at presentation, and had higher incidence rates of antibiotic therapy, non-invasive and invasive mechanical ventilation, and death (11.1% vs. 4.1%). Cox proportional hazard model showed that diabetes (adjusted hazard ratio [aHR]=3.64; 95% confidence interval [CI]: 1.09, 12.21) and fasting blood glucose (aHR=1.19; 95% CI: 1.08, 1.31) were associated with the fatality of COVID-19, adjusting for potential confounders. ConclusionsDiabetes mellitus is associated with greater disease severity and a higher risk of mortality in patients with COVID-19. Primary and secondary prevention strategies are needed for COVID-19 patients with diabetes.

Exploring the role of a nonablative laser (1320 nm cooltouch laser) in skin photorejuvenation.

BACKGROUND: Nonablative laser has been used for the treatment and prevention of skin aging for many years. Although the mechanism has not been elucidated, histological evaluation showed that the dermal fibroblasts and its collagen production should be the main target for this rejuvenation. In order to determine the effects of a 1320 nm nonablative laser on the human dermal fibroblasts, the two main secretion factors, basic fibroblast growth factor (bFGF) and transforming growth factor ß1(TGF-ß1), in vitro were detected. METHODS: The human dermal fibroblasts were cultured and irradiated with a 1320 nm laser at the dose of 15, 20, and 24 J/cm(2) respectively. The number of fibroblasts was counted and the levels of bFGF and TGF-ß1 were detected by enzyme-linked immunosorbent assay at the time points of 0, 24, 48, and 72 h after irradiation. RESULTS: The results showed that both the number of fibroblasts and the secretion of bFGF increased after the irradiation at the dose of 20 and 24 J/cm(2) (P<0.05) compared with that of the control cells. The bFGF secretion in the group exposed to 20 J/cm(2) was more significant than that of 24 J/cm(2), and the peak level was 24 h after irradiation. The level of TGF-ß1 secretion decreased after irradiation in a dose-dependent manner (15 and 20 J/cm(2), both P<0.05; 24 J/cm(2), P<0.01), and reached a nadir at 24 h. CONCLUSION: Our results suggested that the 1320 nm nonablative laser accelerates the vitality of fibroblasts, promotes the secretion of bFGF, and inhibits TGF-ß1 secretion by fibroblasts.

Comparison of mechanical properties of polymethyl methacrylate of different mixing ratios.

OBJECTIVE: To investigate mechanical properties of polymethyl methacrylate (PMMA) of different mixing ratios. METHODS: At 25°C, self-curing denture acrylic and liquid dental base acrylic resin are mixed at mass-volume ratios of 1.5:1, 1:1, 1:1.25, 1:1.5, 1:1.75, 1:2 (g:ml) respectively, and stirred uniformly with a stirring speed of 60 revolutions per minute. A mould of 13 mm diameter and 100 mm length is filled with the mixture, and after it solidifies it is polished. The size of the model is accurate to 0.01 mm. A compression test, tensile test and three-point bending test are conducted. RESULTS: The difference of compressive strength between groups with mixing ratios of 1.5:1 and 1:1 was not significant (p = 0.326). However, the value of compressive strength of each of the first two groups was remarkably higher than that of the latter four groups (p < 0.01). The difference of tensile strength among the first three groups was not significant (p > 0.05), but the value of each groups was significantly higher than in the latter three groups (p < 0.01). Deflection increased with the decrease of mixing ratio. For the first five groups, the value of elastic modulus decreased with the decrease of mixing ratio, which indicated that the rigidity of the test sample decreased accordingly (p < 0.01). CONCLUSION: It can be concluded that PMMAs made from different mixing ratios of powdery polymer and liquid monomer has different mechanical properties. Therefore, during the preparation of PMMA, the mass-volume ratio of the reactants must be taken into precise consideration in order for the result to have optimum performance suitable for making bone substitutes and other applications in orthopaedic surgery.

A study of fractured cranial flap refixation.

OBJECTIVE: To study the techniques of fractured cranial flap refixation (suture, wire and titanium clamps). METHODS: Twenty-four cadaver craniotomy flaps, sawn as fractured flap models, were divided into three groups, and every eight fractured flaps were reattached with sutures, wires and titanium clamps, respectively. Bone flap refixation was timed and measured for offset. For every fixation technique, load-bearing tests were performed on craniotomied skulls by applying an external force until the refixation system failed. The results were compared. RESULTS: The titanium clamp required significantly less time (142+/-16s) to fix than either suture (631+/-47 s) or stainless steel wire (1104+/-48 s). The titanium clamp also showed significantly smaller offset (average offset: 0.35+/-0.07 mm) than either suture (average offset: 1.93+/-0.33 mm) or stainless steel wire (average offset: 1.80+/-0.42 mm). The titanium clamp (maximal force: 384.06+/-24.89 N) was stronger than suture (maximal force 89.43+/-13.76 N) and stainless steel wire (maximal force 285.51+/-10.46 N). CONCLUSION: The titanium clamp is a reasonable alternative method of fractured cranial flap refixation with respect to ease of use, time consumption, accuracy and strength.

Study of hypoxia-induced expression of HIF-1alpha in retina pigment epithelium.

It was shown that the expression of HIF-1alpha in retinal pigment epithelium increased under hypoxic conditions. Eight hours after the start of hypoxic exposure, the expression of HIF-1alpha reached the peak and sustained after 24-hour hypoxia. However, the morphology of PRE cells began to change and the expression of HIF-1alpha decreased after long-term (48-hour) hypoxia. Hypoxia-induced increase in the level of HIF-1alpha in RPE. It can be an important step in choriodal neovascularization.

Study of automatic enhancement for chest radiograph.

Because of the large difference of the densities in the lung and other structures, the chest x-ray image behaves as a wide-range intensity distribution, which brings on a bit of difficulty to investigate the focus. In the paper, according to the intensity properties of the chest radiograph, the chest radiographic image is divided into three subregions, and a piecewise linear transformation model is established. An approach of automatic enhancement is presented, based on the gray-level normalization. The average enhanced ratios of three subregions of the normal and severe acute respiratory syndrome image are increased by 10.70% and 25.55%, respectively. The technique is proved to be effective through the evaluation of the improved images.

Comparisons of hemodynamics in 1-way and 2-way CABG / 生物医学工程学杂志

For the purpose of improving the hemodynamics of CABG, the authors presented a new amelioration measurement of symmetric 2-way bypass graft. The physiological blood flow in 1-way and 2-way bypass graft of coronary is simulated with finite element method, and the data on computational hemodynamics of these two cases were compared. The temporal-spatial distributions of hemodynamics during the cardiac cycle such as flow patterns and wall shear stress in the vicinity of anastomosis were analyzed. The study results showed that 2-way bypass graft was of more rational hemodynamics when compared with 1-way bypass graft, and it could improve the flow conditions and decrease the probability of restenosis.

Biomechanical properties of skin expanded by different methods in vivo / 生物医学工程学杂志

In plastic surgery, people hope the conventional expansion will be replaced by rapid expansion, which can shorten greatly the expansion period. Also people are concerned about whether the skin properties after rapid expansion approach that after conventional expansion. So we designed and made an apparatus for in vivo measurement of tension, and then measured the biomechanical properties of skin in vivo for the first time. The experimental results showed there was no significant difference between the rapid expansion method and conventional expansion method in respect to the area gain of expanded skin surface. Both the tension in vivo and the instant stretch-back ratio increased during the expansion, but fell almost to the control values after four weeks' maintaining period. So, rapid skin expansion did not produce any deleterious effect when compared with the conventional expansion. Extension of the maintaining period can improve the biomechanical properties of expanded skin and effectively reduce the stretch-back ratio. Therefore, rapid expansion with an extended maintaining period is clinically acceptable.

A new approach to detection of QRS complexes based on histogram / 生物医学工程学杂志

A brief comment on the current methods of detecting QRS complexes from ECG(electrocardiogram) including the wavelet transform method is given, and the shortcomings of those methods are discussed. A simple and effective new approach for detecting QRS complexes based on histogram is developed and presented in this paper with a description of the theory of histogram and the match principle for detecting QRS complexes. This new method is checked up on the data from the MIT/BIH ECG database and that from the Beijing Polytechnic University Hospital.

Comparison of biomechanical properties between human nasal periosteum and fascia / 生物医学工程学杂志

There has been a lot of controversies on which layer the silastic implants should be inserted in the augmentation rhinoplasty, i.e. subperiosteal or deep subfascial. This study is to investigate the biomechanical properties of human nasal periosteum and deep fascia, including tensile strength, stress-strain and stress relaxation characters under uniaxial tension system. The periosteum is stronger in tensile strength than that of the fascia, but it is less elastic. Under a sudden increase of load, the periosteum relaxes far less than the fasia. Therefore, in view of biomechanics, the periosteum is thicker, tougher, stiffer and less relaxation than facia, thus has a better fixation effect.

An alternative method of strain analysis on arterial walls / 生物医学工程学杂志

As is well known, the zero stress state of an artery is brought by cutting a ring of the artery radically and then the ring segment springs open into a sector. The zero stress state is a foundation of strain analysis of an artery. There are two methods to measure the dimensions of a blood vessel in the zero stress state. First, it is a way to measure immediately an opening angle. Second, it is a method of assuming that a cut-open, stress-free specimen forms a circular sector and there are two edge angles. In this paper, we proposed a new method to measure the dimensions of an arterial wall in the zero stress state. The new method is to measure immediately the curve length of an arterial wall in zero stress state by computer image process (CIP). We used the curve lengths to define a standard circle for the strain analysis. We compared these three methods on descending thoracic aortas, common carotid arteries, and femoral arteries of white rabbits. Conclusions are: (1) the new method, that is the strain analysis method from the curve length, is the best method among the three methods of strain analysis; (2) the lengths of a ring segment (the length between D/2 and 2D) do not affect the dimensions of the zero stress state.