We experimentally assess the accuracy of a constant output power generalized droop (COP-GD) model combined with transponder implementation penalty to predict transmission performance for single-core ...long-haul optical transmission systems operating at low channel launch powers and high baud rates. The droop model includes Guided Acoustic Waveguide Brillouin Scattering (GAWBS) and nonlinear interference (NLI) effects along with amplifier noise for signal-to-noise ratio (SNR) calculation in the context of long-haul systems with constant output power amplifiers. We show how the model accuracy is decreased if one of the modeling components is removed, namely, either the droop effect, GAWBS or the transponder implementation penalty. We show that inclusion of implementation penalty and GD is important for accurate performance evaluation, moreover, the transponder implementation penalty has impact both at low and high SNR ends. We compare the model including both effects to experimental transmission data over a wide link SNR range for the first time and demonstrate excellent agreement between modeling predictions and experimental results.
The nonreceptor tyrosine TEC kinases are key regulators of the immune system and play a crucial role in the pathogenesis of diverse hematological malignancies. In contrast to the substantial efforts ...in inhibitor development for Bruton's tyrosine kinase (BTK), specific inhibitors of the other TEC kinases, including the bone marrow tyrosine kinase on chromosome X (BMX), remain sparse. Here we present a novel class of dual BMX/BTK inhibitors, which were designed from irreversible inhibitors of Janus kinase (JAK) 3 targeting a cysteine located within the solvent-exposed front region of the ATP binding pocket. Structure-guided design exploiting the differences in the gatekeeper residues enabled the achievement of high selectivity over JAK3 and certain other kinases harboring a sterically demanding residue at this position. The most active compounds inhibited BMX and BTK with apparent IC
values in the single digit nanomolar range or below showing moderate selectivity within the TEC family and potent cellular target engagement. These compounds represent an important first step towards selective chemical probes for the protein kinase BMX.
Forest Stock Volume (FSV) is one of the key indicators in forestry resource investigation and management on local, regional, and national scales. Limited by the saturation problems of optical ...satellite remote-sensing imagery in the retrieving of stock volume, and the high cost of Light Detection And Ranging (LiDAR) data, it is still challenging to estimate FSV in a large area using single-sensor remote-sensing data. In this paper, a method integrated multispectral satellite imagery and LiDAR data was developed to map stock volume in a large area. A random forest model was adopted to estimate the stock volume of larch forest in China based on the training samples from the Airborne Laser Scanning (ALS)-derived stock volume and corresponding Sentinel-2 imagery. Validation using National Forest Inventory (NFI) data, ALS-derived stock volume and ground investigation data demonstrated that the estimated stock volume had a high accuracy (R
2
= 0.59, RMSE = 59.69 m
3
/ha, MD = 39.96 m
3
/ha when validated with NFI data; R
2
ranged from 0.77 to 0.85, RMSE ranged from 38.68 m
3
/ha to 67.38 m
3
/ha, MD ranged from 24.90 m
3
/ha to 37.27 m
3
/ha when validated with ALS stock volume; R
2
= 0.42, RMSE = 79.10 m
3
/ha, MD = 62.06 m
3
/ha when validated with field investigation data). Results of this paper indicated the applicability of estimating stock volume of larch forest in a large area by combining Sentinel-2 data and airborne LiDAR data.
Osteoarthritis (OA) is characterized by persistent destruction of articular cartilage. It has been found that microRNAs (miRNAs) are closely related to the occurrence and development of OA. The ...purpose of the present study was to investigate the mechanism of miR-486 in the development and progression of OA.
The expression levels of miR-486 in cartilage were determined by quantitative real-time polymerase chain reaction (qRT-PCR). The expression of collagen, type II, alpha 1 (COL2A1), aggrecan (ACAN), matrix metalloproteinase (MMP)-13, and a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS4) in SW1353 cells at both messenger RNA (mRNA) and protein levels was determined by qRT-PCR, western blot, and enzyme-linked immunosorbent assay (ELISA). Double luciferase reporter gene assay, qRT-PCR, and western blot assay were used to determine whether silencing information regulator 6 (SIRT6) was involved in miR-486 induction of chondrocyte-like cells to a more catabolic phenotype.
Compared with osteonecrosis, the expression of miR-486 was significantly upregulated in cartilage from subjects with severe OA. In addition, overexpressed miR-486 promoted a catabolic phenotype in SW1353 cells by upregulating the expressions of ADAMTS4 and MMP-13 and down-regulating the expressions of COL2A1 and ACAN. Conversely, inhibition of miR-486 had the opposite effect. Furthermore, overexpression of miR-486 significantly inhibited the expression of SIRT6, confirming that SIRT6 is a direct target of miR-486. Moreover, SW1353 cells were transfected with small interfering RNA (si)-SIRT6 and it was found that SIRT6 was involved in and inhibited miR-486-induced changes to SW1353 gene expression.
Our results indicate that miR-486 promotes a catabolic phenotype in SW1353 cells in OA by targeting SIRT6. Our findings might provide a potential therapeutic target and theoretical basis for OA. Cite this article:
2021;10(7):459-466.
Disinfection by-products (DBPs) are the most common organic contaminants in tap water and are of wide concern because of their highly developmental toxic, cytotoxic, and carcinogenic properties. ...Typically, to control the proliferation of pathogenic microorganisms, a certain concentration of residual chlorine is retained in the factory water, which reacts with the natural organic matter and the disinfection by-products that have been formed, thus affecting the determination of DBPs. Therefore, to obtain an accurate concentration, residual chlorine in tap water needs to be quenched prior to treatment. Currently, the most commonly used quenching agents are ascorbic acid, sodium thiosulfate, ammonium chloride, sodium sulfite, and sodium arsenite, but these quenching agents can cause varying degrees of DBPs degradation. Therefore, in recent years, researchers have attempted to find emerging chlorine quenchers. However, no studies have been conducted to systematically review the effects of traditional quenchers and new ones on DBPs, as well as their advantages, disadvantages, and scope of application. For inorganic DBPs (bromate, chlorate, and chlorite), sodium sulfite has been proven to be the ideal chlorine quencher. For organic DBPs, although ascorbic acid caused the degradation of some DBPs, it remains the ideal quenching agent for most known DBPs. Among the studied emerging chlorine quenchers, n-acetylcysteine (NAC), glutathione (GSH), and 1,3,5-trimethoxybenzene are promising for their application as the ideal chlorine quencher of organic DBPs. The dehalogenation of trichloronitromethane, trichloroacetonitrile, trichloroacetamide, and bromochlorophenol by sodium sulfite is caused by nucleophilic substitution reaction. This paper takes the understanding of DBPs and traditional and emerging chlorine quenchers as a starting point to comprehensively summarize their effects on different types of DBPs, and to provide assistance in understanding and selecting the most suitable residual chlorine quenchers during DBPs research.
Abstract
Background
Vertigo and dizziness (VD) are among the most frequently seen symptoms in clinics and are important for medical students, especially for those in Chinese standardized residency ...training (SRT). The aim of our study was to examine the PAL method’s feasibility in the clinical teaching of VD-related diseases for SRT students in China.
Methods
This is a randomized, controlled, multicenter study. A total of 228 residents were invited to participate in this study, of which 198 completed the program. The students were randomized into two groups, and VD-related diseases were taught using lecture-based learning (control group) or peer-assisted learning (PAL). An examination paper and a rating scale were used to evaluate students’ performance in the mastery of VD-related theoretical knowledge and clinical skills, meanwhile students’ perceptions, satisfaction, and risk of burnout were also analyzed using a questionnaire. Independent-samples
t
-test and chi-square analysis were performed to evaluate statistical significance for continuous variables and categorical variables, respectively, using SPSS 18.0 software.
Results
The PAL group performed better in mastering theoretical knowledge and clinical skills than the control group. And more students believed that PAL could help improve their personal qualities such as teamwork skills. However, more students reported that PAL increased the risk of burnout.
Conclusions
PAL was a suitable and effective method in the clinical teaching of some specialized diseases, especially it was recommended for students who had gained initial knowledge and skills, such as Chinese SRT students. However, we should draw attention to the increased risk of burnout if PAL is intended to be widely used in clinical teaching.
Trial registration
ISRCTN registry,
ISRCTN53773239
, 05/07/2021, retrospectively registered.
To investigate the effectiveness of tibialis posterior tendon transfer for foot drop secondary to peroneal nerve palsy.
The clinical data of 21 patients with unilateral foot drop secondary to ...peroneal nerve palsy between October 2009 and September 2016 was retrospectively analyzed. There were 12 males and 9 females with an average age of 32.1 years (range, 23-47 years). The causes of peroneal nerve injury were iatrogenic injury in 7 cases, tibiofibular fractures combined with compartment syndrome in 5 cases, nerve exploration surgery after stab or cut injury in 3 cases, direct violence in 4 cases, and the fibular head fracture in 2 cases. The average time from injury to operation was 5.6 years (range, 2-8 years). There was 1 case of hallux valgus and 5 cases of toe flexion contracture. The American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot scores, Foot and Ankle Ability Measure (FAAM) scores, range of motion (ROM), and dorsiflexion strength of ankle joint were used to evaluated the ankle f
To compare the clinical and radiographic outcomes of bioabsorbable screw and metallic screw for Maisonneuve fracture.
The clinical data of 68 patients of Maisonneuve fracture treated with open ...reduction and internal fixation between October 2012 and October 2016 were retrospectively analyzed. Metallic screw fixation was used in 37 cases (group A) and absorbable screw fixation was used in 31 cases (group B). There was no significant difference in age, gender, weight, operated side, cause of injury, time from injury to operation, and complications between the two groups (
>0.05). At last follow-up, the tibiafibular clear space (TFCS), tibiafibular overlap (TFO), medial clear space (MCS), and syndesmotic malreduction rate were recorded. And the dorsiflexion and plantar-flexion range of motion, pain visual analogue scale (VAS) score, ankle and hind foot score of American Orthopaedic Foot and Ankle Society (AOFAS), and Olerud-Molander (OM) score were recorded.
All patients were followed up 25-43 months, with an av
A recursive perturbation theory to model the fiber-optic system is developed. Using this perturbation theory, a multi-stage compensation technique to mitigate the intra-channel nonlinear impairments ...is investigated. The technique is validated by numerical simulations of a single-polarization single-channel fiber-optic system operating at 28 Gbaud, 32-quadrature amplitude modulation (32-QAM), and 40 × 80 km transmission distance. It is found that, with 2 samples per symbol, the multi-stage scheme with eight compensation stages increases the Q-factor as compared with linear compensation by 4.5 dB; as compared with single-stage compensation, the computational complexity is reduced by a factor of 1.3 and the required memory for storing perturbation coefficients is decreased by a factor of 13.
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