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Background: Perioperative neurocognitive disorders (PND) occur frequently in elderly patients after surgery, but the mechanism of PND is not very clear at present. It is reported that anesthesia/surgery could cause intestinal flora imbalance and induce neurocognitive impairment. However, the effect of intestinal flora on PND is poorly understood. We previously found that peripheral interleukin-17A (IL17A) destroyed the blood-brain barrier (BBB), leading to central inflammation and neurocognitive impairment. The small intestine is the main place where Th17 cells are produced. Therefore, we hypothesized that Th17 cells and IL-17 may be an important bridge for intestinal microbes to cause neuroinflammation. Methods: Exploratory laparotomy was performed to establish PND model under sevoflurane anesthesia. 16S rRNA high-throughput sequencing was used to detect the changes of intestinal flora. To explore the relationship between intestinal flora and PND, compound antibiotics were used to eliminate intestinal flora before anesthesia/surgery, and behavior tests, such as open field, Y maze, and fear conditioning tests were applied to detect the changes of memory ability and which was compared with the rats that did not receive compound antibiotics. The number of Th17 cells and Foxp3 cells was detected by flow cytometry in the Peyer's patches (PP), mesenteric lymph nodes (MLN), blood and brain. Hippocampus IL17, IL17RA, IL6 and IL10 were detected by Western blot. Hippocampus IL17, IL17R and IBA1 (ionized calcium binding adaptor molecule1) were detected by immunofluorescence. Results: Anesthesia/surgery caused intestinal flora imbalance and induced neurocognitive impairment, increased the number of Th17 cells in the PP, MLN, blood and brain, up-regulated the lever of IL17, IL17R and inflammatory factor production in the hippocampus. The administration of compound antibiotics before anesthesia/surgery evidently inhibited this effect, including decreased the number of Th17 cells, down-regulated the lever of IL17, IL17R and inflammatory factor production, and improved the memory function. In addition, we found that IL17R was co-labeled with IBA1 in a large amount in the hippocampus through immunofluorescence double-staining. Conclusion: Our study suggested that intestinal dysbacteriosis-propelled T helper 17 cells activation might play an important role in the pathogenesis of PND.

To control the COVID-19 pandemic and prevent its resurgence in areas preparing for a return of economic activities, a method for a rapid, simple, and inexpensive point-of-care diagnosis and mass screening is urgently needed. We developed and evaluated a one-step colorimetric reverse-transcriptional loop-mediated isothermal amplification assay (COVID-19-LAMP) for detection of SARS-CoV-2, using SARS-CoV-2 isolate and respiratory samples from patients with COVID-19 (n = 223) and other respiratory virus infections (n = 143). The assay involves simple equipment and techniques and low cost, without the need for expensive qPCR machines, and the result, indicated by color change, is easily interpreted by naked eyes. COVID-19-LAMP can detect SARS-CoV-2 RNA with detection limit of 42 copies/reaction. Of 223 respiratory samples positive for SARS-CoV-2 by qRT-PCR, 212 and 219 were positive by COVID-19-LAMP at 60 and 90 min (sensitivities of 95.07% and 98.21%) respectively, with the highest sensitivities among nasopharyngeal swabs (96.88% and 98.96%), compared to sputum/deep throat saliva samples (94.03% and 97.02%), and throat swab samples (93.33% and 98.33%). None of the 143 samples with other respiratory viruses were positive by COVID-19-LAMP, showing 100% specificity. Samples with higher viral load showed shorter detection time, some as early as 30 min. This inexpensive, highly sensitive and specific COVID-19-LAMP assay can be useful for rapid deployment as mobile diagnostic units to resource-limiting areas for point-of-care diagnosis, and for unlimited high-throughput mass screening at borders to reduce cross-regional transmission.

Kinesiology tape (KinTape) is a therapeutic tape without much understanding of its mechanism. KinTape claims to increase cutaneous stimulation, which facilitates motor unit firing, and consequently improves functional performance; however these, benefits could be due to placebo effects. This study investigated the true effects of KinTape by a deceptive, randomized, and controlled trial. Thirty healthy participants performed isokinetic testing of three taping conditions: true facilitative KinTape, sham KinTape, and no KinTape. The participants were blindfolded during the evaluation. Under the pretense of applying adhesive muscle sensors, KinTape was applied to their quadriceps in the first two conditions. Normalized peak torque, normalized total work, and time to peak torque were measured at two angular speeds (60°/s and 180°/s) and analyzed with one-way repeated measures ANOVA. Participants were successfully deceived and they were ignorant about KinTape. No significant differences were found between normalized peak torque, normalized total work, and time to peak torque at 60°/s or 180°/s (p = 0.31-0.99) between three taping conditions. The results showed that KinTape did not facilitate muscle performance in generating higher peak torque, yielding a greater total work, or inducing an earlier onset of peak torque. These findings suggest that previously reported muscle facilitatory effects using KinTape may be attributed to placebo effects.

The performance of tunnel safety systems for fire protection and ventilation provision is evaluated using Computational Fluid Dynamics (CFD). Ventilation safety systems commonly used in tunnels are reviewed first. The safety aspects related to tunnel fire and ventilation are then discussed. Air flow induced by an accidental vehicular fire in a tunnel is simulated using CFD. Based on the results, performances of different safety systems are evaluated and compared. Systems considered are longitudinal, semi-transverse, transverse, partial transverse, and combined longitudinal and semi-transverse ventilation systems. Furthermore, sensitivity analyses on the effects of the grid size, and number of iterations on the required computing time and accuracy of the results are carried out.

A vehicle fire occurred in a cross-harbour tunnel in Hong Kong in May 2000. In that accident, nobody was hurt, but the traffic was blocked for several hours, leading to huge economic losses. A general description of the fire is reported. Regarding the safety requirements of the tunnel, the performance of the fire fighting systems is reviewed. Fire safety management in that incident is discussed and recommendations are made to the authority for better fire safety management. To improve the outdoor air quality, the Government is trying to replace diesel vehicles with liquefied petroleum gas (LPG) vehicles. Fire safety aspects of running LPG cars in tunnels are also discussed.

Consequent to a recent fire resulting from a truck carrying illegal diesel outside a tunnel in Hong Kong, people are quite concerned about the safety aspects of vehicular tunnels. That truck was an ordinary vehicle without appropriate protection against the possible accidental fires due to those liquid fuels. The safety impact on a vehicular tunnel of a fire in an unprotected truck carrying illegal diesel is studied in this paper. Empirical results on spill fires and cooling jet expressions were applied to assess the probable tunnel environment. The two-layer zone model CFAST was also used to verify the results. The smoke temperature in the tunnel within 100 m of the fire might be up to 300°C, and smoke would travel rapidly. It is recommended that a proper safety management scheme should be worked out by the tunnel management authority. If necessary, every truck of enclosed structure should be inspected before entering a vehicular tunnel longer than a specified length, say 230 m.

The aim of this study was to obtain quantitative information from published data on the association between environmental tobacco smoke (ETS) exposure and the prevalence of serious lower respiratory tract infections (LRTI) in infancy and early childhood. We identified 21 relevant publications on the relation between ETS and the prevalence of serious LRTI by reviewing reference lists in relevant reports and by conducting manual and computer searches (Medline database; Dissertation abstracts index of Xerox University Microfilms) of published reports between 1966 and 1995. Thirteen studies were included in a quantitative overview using random effects modeling to derive pooled odds ratios. Sensitivity analyses were conducted to test the decision rules used in extracting odds ratio data. The results of community and hospital studies are broadly consistent and show that the child of a parent who smokes is at approximately twice the risk of having a serious respiratory tract infection in early life that requires hospitalization. This association was pronounced in children younger than age two and diminished after the age of two. The combined odds ratio for hospitalization for lower respiratory tract infections in infancy or early childhood is 1.93 (95% CI 1.66-2.25); the combined odds ratio of prevalence of serious LRTI at age less than 2 years, between 0 and 6 years, and between 3 and 6 years were 1.71 (95% CI 1.33-2.20); 1.57 (1.28-1.91), and 1.25 (0.88-1.78), respectively. There was no evidence of heterogeneity across the studies in these combined odds ratios. We conclude that this meta-analysis provides strong evidence that exposure to ETS causes adverse respiratory health outcomes such as either a serious LRTI or hospitalization for LRTI. New public health campaigns are urgently needed to discourage smoking in the presence of young children.

Safety requirement and regulations on fire and ventilation for tunnels in the Hong Kong Special Administrative Region (HKSAR, formerly Hong Kong) are reviewed. Both vehicular and railway tunnels are considered. Vehicle emissions are important for vehicular tunnels and so discussions on carbon monoxide from petrol engines and particulates from diesel engines are reported. Better environmental control on air temperature, air velocity and air pressure are also discussed. Problems to be considered for future tunnel design along these two areas are identified.

Background: We urgently need to take steps towards reducing the prevalence of asthma in countries where the prevalence has become unacceptably high in recent years. Because we do not have any good information about causes of the increased prevalence, we cannot act directly to reverse the trend. Therefore we need to take an indirect approach and use known information of etiologic factors to try to reduce asthma in the next generation, while acknowledging that we may be dealing with different factors from those responsible for the increased prevalence. Any successful strategies will also help to ensure that developing countries do not attain such high rates of asthma in their children in coming years. Objective: This article summarizes the roles of the risk factors that identify "high-risk" children, that provide insights into mechanisms, or that have potential for primary prevention. The factors with the most potential for primary prevention are allergen exposure, parental smoking, breast-feeding, and dietary fatty acids. Conclusion: In other health models, information about risk factors has been used in successful public health interventions. It is disappointing that the important risk factors for asthma are well documented but that there have been few trials of primary prevention and no changes in public health policies. (J Allergy Clin Immunol 1999;103:1-10.)

Ossicles located at the acetabular rim are generally referred to as unfused secondary ossification centres and are named “os acetabuli”. They are also observed in severely dysplastic hips, where they are considered as fatigue fractures of the acetabular rim due to overload. In a retrospective study, we evaluated the radiographs of 495 patients, who were treated surgically for femoro-acetabular impingement. In 18 hips (15 patients) a large osseous fragment at the anterolateral acetabular rim was found. All patients presented radiographically with a femoral head showing an aspherical extension producing a “cam” impingement. Sixteen hips had a retroverted acetabulum, indicating anterior overcover. Preoperative MRIs available in 12 patients showed the presence of a fragment composed of labrum, articular cartilage and bone. The gap between the stable acetabulum and the rim fragment had a vertical orientation. All patients had been exposed to a physically demanding profession or contact sport and in 15 hips no memorable traumatic episode was present. The mechanism leading to this acetabular rim fragment is thought to be fatiguing due to femoro-acetabular impingement. The aspheric portion of the head is jammed into the acetabulum and with time causes a stress fracture of the retroverted portion of the acetabulum. True “Os acetabuli” are morphologically similar, but the orientation of the cartilaginous growth plate is more parallel to the joint surface, in contrast to the hips in the current study, where the separation line was perpendicular to the joint surface. The clinical importance is that the presence of an acetabular rim fragment in the non-dysplastic hip must raise suspicion of femoro-acetabular impingement.

An exact analytical solution within the linear framework is developed for the transient dynamic impact response of a two-end simply supported cylindrical shell of finite length. The solution obtained is shown to consist of a remarkably simple analytical expression. Several examples of impact loadings are calculated. The results show excellent agreement with those of the computer code ABAQUS.

Concern regarding the safety of Carotid angioplasty and stenting (CAS) exists because of the risk of cerebral embolization during the procedure. The purpose of this article is to discuss that technology modification may improve the outcomes of this procedure. Between October 1997 and October 2004, 439 consecutive patients with 478 stenotic carotid arteries were treated. 284 vessels were stented without the use of embolic protection devices and 194 vessels with protection. Among cases not using protection device, 201 arteries were stented with predilation alone, 63 with postdilation alone, six with both pre- and post-dilation, two with neither and twelve were stented with balloon expandable stents. The technical success of 100%. The combined stroke and death rate during the procedure and the 30-day follow-up at 30 days was 1.67% overall. Three (0.63%) deaths occurred; one was due to a major infarction secondary to stent breakage, and two died of massive reperfusion intracerebral haemorrhage. There were total six ischemic stroke, of the five ischemic strokes wich developed in nonprotection group, two were among 201 cases with predilation alone (0.99%), which developed after stent deployment and postprocedure, and three among 63 cases with postdilation alone (4.76%), which developed immediately after postdilation. The incidence of ischemic stroke was lower among those who were stented with predilation alone than among those who were stented with postdilation alone. This likely results from reduced intimal injury and decreased risk of embolic complications

Si/SiGe n-channel modulation-doped field effect transistors (MODFETs) have been fabricated on a 10 /spl mu/m-thick membrane by removal of the Si substrate and SiGe virtual substrate under the device layers. The membrane devices, surrounded by air, were characterised after thinning and compared to the unthinned characteristics. A large reduction of the off-currents of the MODFETs on air, due to an increase in substrate resistance, has been measured, making them more suitable for low-power applications.