Transporting randomized trial results to estimate counterfactual survival functions in target populations.

When the distributions of treatment effect modifiers differ between a randomized trial and an external target population, the sample average treatment effect in the trial may be substantially different from the target population average treatment, and accurate estimation of the latter requires adjusting for the differential distribution of effect modifiers. Despite the increasingly rich literature on transportability, little attention has been devoted to methods for transporting trial results to estimate counterfactual survival functions in target populations, when the primary outcome is time to event and subject to right censoring. In this article, we study inverse probability weighting and doubly robust estimators to estimate counterfactual survival functions and the target average survival treatment effect in the target population, and provide their respective approximate variance estimators. We focus on a common scenario where the target population information is observed only through a complex survey, and elucidate how the survey weights can be incorporated into each estimator we considered. Simulation studies are conducted to examine the finite-sample performances of the proposed estimators in terms of bias, efficiency and coverage, under both correct and incorrect model specifications. Finally, we apply the proposed method to assess transportability of the results in the Action to Control Cardiovascular Risk in Diabetes-Blood Pressure (ACCORD-BP) trial to all adults with Diabetes in the United States.

HIV transmission and associated factors under the scale-up of HIV antiretroviral therapy: a population-based longitudinal molecular network study.

OBJECTIVES: To evaluate the prevention efficacy of scaling up HIV/AIDS antiretroviral therapy (ART) on HIV transmission at the population level and determine associated factors of HIV secondary transmission. METHODS: We used HIV longitudinal molecular networks to assess the genetic linkage between baseline and newly diagnosed cases. A generalized estimating equation was applied to determine the associations between demographic, clinical characteristics and HIV transmission. RESULTS: Patients on ART had a 32% lower risk of HIV transmission than those not on ART. A 36% reduction in risk was also seen if ART-patients maintained their HIV viral load lower than 50 copies/mL. A 71% lower risk occurred when patients sustained ART for at least 3 years and kept HIV viral load less than 50 copies/mL. Patients who discontinued ART had a similar HIV transmission risk as those not on ART. Patients who were older, male, non-Han, not single, retired, infected via a heterosexual route of transmission and those who possessed higher CD4 counts had a higher risk of HIV transmission. HIV-1 subtype of CRF01_AE was less transmissible than other subtypes. CONCLUSIONS: The efficacy of ART in a real-world setting was supported by this longitudinal molecular network study. Promoting adherence to ART is crucial to reduce HIV transmission.

Exploration of thoracoabdominal aortic mixed reality optimisation and its clinical application value in type A aortic dissection.

OBJECTIVES: This study aimed to explore the feasibility of low-dose computed tomography (CT)-based mixed reality and its clinical role in type A aortic dissection (TAAD) operations. METHODS: Eighty-seven patients diagnosed with TAAD were prospectively enrolled and underwent thoracoabdominal aorta mixed reality. They were randomly divided into a low-dose mixed reality group, a conventional mixed reality group and a conventional thoracoabdominal aorta computed tomography angiography (CTA) group. Three-dimensional modelling, mixed reality and CT reconstruction technology were selected. The radiation dose and image quality were compared using Student's t test. Doctors with different seniorities evaluated the clinical application value of thoracoabdominal aorta mixed reality using a Likert scale. The consistency was assessed using the Cohen kappa coefficient (k). The Pearson chi-square test was used to test the correlation of perioperative index results in TAAD operations. RESULTS: Low-dose CT technology can be effectively applied to thoracoabdominal aorta mixed reality and reduces the radiation dose by approximately 59% and the operation time and auxiliary cardiopulmonary bypass time by approximately 22% and 29%, respectively. The subjective scores of doctors with different seniorities on the clinical application value of thoracoabdominal aorta mixed reality were higher than those of thoracoabdominal aorta CTA (all p > 0.05). CONCLUSIONS: Low-dose CT can be effectively used in thoracoabdominal aortic mixed reality to reduce the radiation dose while ensuring quality. Low-dose thoracoabdominal aortic mixed reality has clinical application value and can effectively reduce the operation time and auxiliary cardiopulmonary bypass time in TAAD operations. KEY POINTS: • Low-dose CT technology can ensure the mixed reality quality of the thoracoabdominal aorta with a radiation dose reduction of approximately 59%. • Compared with thoracoabdominal aorta CTA, low-dose thoracoabdominal aorta mixed reality can reduce the operation time and auxiliary cardiopulmonary bypass time by approximately 20% and 29%, respectively, in TAAD operations. • The application value of low-dose thoracoabdominal aorta mixed reality in operation scheme formulation, operation risk assessment, operation navigation and diagnosis and treatment under safe distance was greater than that of thoracoabdominal aorta CTA in TAAD.

Fouling-resistant zwitterionic polymers for complete prevention of postoperative adhesion.

Postoperative adhesions are most common issues for almost any types of abdominal and pelvic surgery, leading to adverse consequences. Pharmacological treatments and physical barrier devices are two main approaches to address postoperative adhesions but can only alleviate or reduce adhesions to some extent. There is an urgent need for a reliable approach to completely prevent postoperative adhesions and to significantly improve the clinical outcomes, which, however, is unmet with current technologies. Here we report that by applying a viscous, cream-like yet injectable zwitterionic polymer solution to the traumatized surface, postoperative adhesion was completely and reliably prevented in three clinically relevant but increasingly challenging models in rats. The success rate of full prevention is over 93% among 42 animals tested, which is a major leap in antiadhesion performance. Clinically used Interceed film can hardly prevent the adhesion in any of these models. Unlike current antiadhesion materials serving solely as physical barriers, the "nonfouling" zwitterionic polymer functioned as a protective layer for antiadhesion applications with the inherent benefit of resisting protein/cell adhesions. The nonfouling nature of the polymer prevented the absorption of fibronectins and fibroblasts, which contribute to the initial and late-stage development of the adhesion, respectively. This is the key working mechanism that differentiated our "complete prevention" approach from current underperforming antiadhesion materials. This work implies a safe, effective, and convenient way to fully prevent postoperative adhesions suffered by current surgical patients.

Topical astilbin ameliorates imiquimod-induced psoriasis-like skin lesions in SKH-1 mice via suppression dendritic cell-Th17 inflammation axis.

Astilbin, an essential component of Rhizoma smilacis glabrae, exerts significant antioxidant and anti-inflammatory effects against various autoimmune diseases. We have previously reported that astilbin decreases proliferation and improves differentiation of HaCaT keratinocytes in a psoriatic model. The present study was designed to evaluate the potential therapeutic effects of topical administration of astilbin on an imiquimod (IMQ)-induced psoriasis-like murine model and to reveal their underlying mechanisms. Topical administration of astilbin at a lower dose alleviated IMQ-induced psoriasis-like skin lesions by inducing the differentiation of epidermal keratinocytes in mice, and the therapeutic effect was even better than that of calcipotriol. Moreover, the inflammatory skin disorder was relieved by astilbin treatment characterized by a reduction in both IL-17-producing T cell accumulation and psoriasis-specific cytokine expression in skin lesions. Furthermore, we found that astilbin inhibited R837-induced maturation and activation of bone marrow-derived dendritic cells and decreased the expression of pro-inflammatory cytokines by downregulating myeloid differentiation factor 88. Our findings provide the convincing evidence that lower doses of astilbin might attenuate psoriasis by interfering with the abnormal activation and differentiation of keratinocytes and accumulation of IL-17-producing T cells in skin lesions. Our results strongly support the pre-clinical application of astilbin for psoriasis treatment.

Approximate profile likelihood estimation for Cox regression with covariate measurement error.

In nutritional epidemiology, measurement error in covariates is a well-known problem since dietary intakes are usually assessed through self-reporting. In this article, we consider an additive error model in which error variables are highly correlated, and propose a new method called approximate profile likelihood estimation (APLE) for covariates measured with error in the Cox regression. Asymptotic normality of this estimator is established under regularity conditions, and simulation studies are conducted to examine the finite sample performance of the proposed estimator empirically. Moreover, the popular correction method called regression calibration is shown to be a special case of APLE. We then apply APLE to deal with measurement error in some nutrients of interest in the EPIC-InterAct Study under a sensitivity analysis framework.

Biodegradable Zwitterionic Cream Gel for Effective Prevention of Postoperative Adhesion.

Postoperative peritoneal adhesions were frequent complications for almost any types of abdominal and pelvic surgery. This led to numerous medical problems and huge financial burden to the patients. Current anti-adhesion strategies focused mostly on physical barriers including films and hydrogels. However, they can only alleviate or reduce adhesions to certain level and their applying processes were far from ideal. This work reported the development of a biodegradable zwitterionic cream gel presenting a series of characters for an idea anti-adhesion material, including unique injectable yet malleable and self-supporting properties, which enabled an instant topical application, no curing, waiting or suturing, no hemostasis requirement, protein/cell resistance and biodegradability. The cream gel showed a major advancement in anti-adhesion efficacy by completely and reliably preventing a primary and a more severe recurrent adhesion in rat models.

Survey of pretreatment HIV drug resistance and the genetic transmission networks among HIV-positive individuals in southwestern China, 2014-2020.

BACKGROUND: Pretreatment drug resistance (PDR) can limit the effectiveness of HIV antiretroviral therapy (ART). The aim of this study was to assess the prevalence of PDR among HIV-positive individuals that initiated antiretroviral therapy in 2014-2020 in southwestern China. METHODS: Consecutive cross-sectional surveys were conducted in Qinzhou, Guangxi. We obtained blood samples from individuals who were newly diagnosed with HIV in 2014-2020. PDR and genetic networks analyses were performed by HIV-1 pol sequences using the Stanford HIV-database algorithm and HIV-TRACE, respectively. Univariate and multivariate logistic regression models were used to explore the potential factors associated with PDR. RESULTS: In total, 3236 eligible HIV-positive individuals were included. The overall prevalence of PDR was 6.0% (194/3236). The PDR frequency to NNRTI (3.3%) was much higher than that of NRTI (1.7%, p < 0.001) and PI (1.2%, p < 0.001). A multivariate logistic regression analysis revealed that PDR was significantly higher among individuals aged 18-29 (adjusted odds ratio (aOR): 1.79, 95% CI 1.28-2.50) or 30-49 (aOR: 2.82, 95% CI 1.73-4.82), and harboring CRF08_BC (aOR: 3.23, 95% CI 1.58-6.59). A total of 1429 (43.8%) sequences were linked forming transmission clusters ranging in size from 2 to 119 individuals. Twenty-two individuals in 10 clusters had the same drug resistant mutations (DRMs), mostly to NNRTIs (50%, 5/10). CONCLUSIONS: The overall prevalence of PDR was medium, numerous cases of the same DRMs among genetically linked individuals in networks further illustrated the importance of surveillance studies for mitigating PDR.

Plastic shed production systems: The migration of heavy metals from soil to vegetables and human health risk assessment.

Plastic shed production system (PSPS) provide abundant vegetable products for human consumption. Comprehensive and accurate heavy metal (HM) risk assessment of soil and vegetable under plastic sheds is crucial for human health. Pollution assessment, bioavailability and mobility evaluation and health risk assessment of Cd, Cr, Cu, Zn Ni, Pb, and As were performed in a presentative Plastic shed production system. The concentrations of the Cd, Cu and Zn exceeded their background value. Positive Igeo values suggested that soil under plastic sheds was widely contaminated with Cd. The bioavailability of heavy metals in soils was evaluated using DTPA extraction and DGT methods. The results of both methods demonstrated that Cd, Cu, and Zn have high bioavailability, especially Cd. Analogically, the results of mobility assignment based on DIFS showed that Cd has a high migration risk due to the large available pool. Based on specific cultivation and management patterns of plastic shed production system, pH reduction and salt and nutrient accumulation may increase the heavy metals migration risk in soil under plastic sheds, while a high organic matter content may reduce the heavy metals migration risk. The average concentrations of Cd, Cr, Cu, Zn, Ni, Pb, and As in vegetables were 0.023, 0.226, 0.654, 2.984, 0.329, 0.041, and 0.010 mg/kg, respectively. All samples were well below the threshold. The order of target hazard quotient of different heavy metals caused by vegetable consumption was Cd > Cr > As > Cu, Ni, Pb, Zn, and the average total hazard index value was below 1, which demonstrated that risk of vegetable consumption in the study area. However, due to its high concentration and transfer coefficient in spinach, Cd might pose a health risk to humans, which requires special attention. In this study, Cd caused a significant issue than other HMs, whether pollution level, health risk and migration risk. DGT and DIFS can be used as an effective evaluation tool in the research of controlling heavy metals migration in soil-crop systems.

Approximate maximum likelihood estimation for logistic regression with covariate measurement error.

In nutritional epidemiology, dietary intake assessed with a food frequency questionnaire is prone to measurement error. Ignoring the measurement error in covariates causes estimates to be biased and leads to a loss of power. In this paper, we consider an additive error model according to the characteristics of the European Prospective Investigation into Cancer and Nutrition (EPIC)-InterAct Study data, and derive an approximate maximum likelihood estimation (AMLE) for covariates with measurement error under logistic regression. This method can be regarded as an adjusted version of regression calibration and can provide an approximate consistent estimator. Asymptotic normality of this estimator is established under regularity conditions, and simulation studies are conducted to empirically examine the finite sample performance of the proposed method. We apply AMLE to deal with measurement errors in some interested nutrients of the EPIC-InterAct Study under a sensitivity analysis framework.

Efficient n-Doping of Polymeric Semiconductors through Controlling the Dynamics of Solution-State Polymer Aggregates.

Doping of polymeric semiconductors limits the miscibility between polymers and dopants. Although significant efforts have been devoted to enhancing miscibility through chemical modification, the electrical conductivities of n-doped polymeric semiconductors are usually below 10 S cm-1 . We report a different approach to overcome the miscibility issue by modulating the solution-state aggregates of conjugated polymers. We found that the solution-state aggregates of conjugated polymers not only changed with solvent and temperature but also changed with solution aging time. Modulating the solution-state polymer aggregates can directly influence their solid-state microstructures and miscibility with dopants. As a result, both high doping efficiency and high charge-carrier mobility were simultaneously obtained. The n-doped electrical conductivity of P(PzDPP-CT2) can be tuned up to 32.1 S cm-1 . This method can also be used to improve the doping efficiency of other polymer systems (e.g. N2200) with different aggregation tendencies and behaviors.

A Method of Multiple Dynamic Objects Identification and Localization Based on Laser and RFID.

In an indoor environment, object identification and localization are paramount for human-object interaction. Visual or laser-based sensors can achieve the identification and localization of the object based on its appearance, but these approaches are computationally expensive and not robust against the environment with obstacles. Radio Frequency Identification (RFID) has a unique tag ID to identify the object, but it cannot accurately locate it. Therefore, in this paper, the data of RFID and laser range finder are fused for the better identification and localization of multiple dynamic objects in an indoor environment. The main method is to use the laser range finder to estimate the radial velocities of objects in a certain environment, and match them with the object's radial velocities estimated by the RFID phase. The method also uses a fixed time series as "sliding time window" to find the cluster with the highest similarity of each RFID tag in each window. Moreover, the Pearson correlation coefficient (PCC) is used in the update stage of the particle filter (PF) to estimate the moving path of each cluster in order to improve the accuracy in a complex environment with obstacles. The experiments were verified by a SCITOS G5 robot. The results show that this method can achieve an matching rate of 90.18% and a localization accuracy of 0.33m in an environment with the presence of obstacles. This method effectively improves the matching rate and localization accuracy of multiple objects in indoor scenes when compared to the Bray-Curtis (BC) similarity matching-based approach as well as the particle filter-based approach.

In vivo research on Cu-bearing ureteral stent.

Infection and encrustation limit the use of ureteral stent and to data no device can completely solve these complications. The Cu-bearing stainless steel is a novel material with properties of inhibiting infection and decreasing encrustation in vitro. In this work, ureteral stents were fabricated and implanted into the bladder of New Zealand rabbits, aiming to further investigate the effects of material on bacterial survival and growth as well as the implant related encrustation. Less adherent microbes and deposited crystals on Cu-bearing stainless steel stents were found, with significant differences in comparison with stainless steel stents, which further support the development of biofunctional ureteral stents.

Magnetoresistive sensors based on the elasticity of domain walls.

Magnetic sensors based on magnetoresistance effects have promising application prospects due to their excellent sensitivity and their advantages in terms of integration. However, the competition between higher sensitivity and a larger measuring range remains a problem. Here, we propose a novel mechanism for designing magnetoresistive sensors: probing the perpendicular field by detecting the expansion of the elastic magnetic domain wall in the free layer of a spin valve or a magnetic tunnel junction. The performances of devices based on this mechanism, such as the sensitivity and the measuring range, can be tuned by manipulating the geometry of the device. This can be achieved without changing the intrinsic properties of the material, thus promising a higher integration level and a better performance. The mechanism is theoretically explained based on the experimental results. Two examples are proposed and their functionality and performances are verified via a micromagnetic simulation.

Effects of health-related quality of life on health service utilisation in patients with colorectal neoplasms.

This study was to assess the impact of HRQOL on health service utilisation using four different count data models. The HRQOL was measured using the Short-Form Six-Dimension instrument and the functional assessment of cancer therapy-colorectal whereas health service utilisation was measured by the number of monthly clinical consultations and the number of monthly hospitalisation. Different count data models (Poisson's regression, negative binomial regression, zero-inflated Poisson's regression and zero-inflated negative binomial regression) were used to assess the association between HRQOL and health service utilisation. A performance comparison was made between the models. Goodness-of-fit statistics (the Pearson's chi-squared test statistic, the Akaike and Bayesian information criteria) were used to determine the best-fitting model. The negative binomial model performed the best in assessing the association between HRQOL measures and health service utilisation in patients with colorectal neoplasm and thus recommended. Physical well-being of patients was negatively and significantly associated with the monthly rate of health service utilisation after controlling for patient demographics. Both physical and function well-beings of patients were negatively and significantly associated with the number of monthly hospitalisations. If the data for the condition-specific FACT-C are not available, SF-6D showed a very strong negative relationship with health service utilisation. Such models can be used to guide the allocation of clinical resources and funding for the care of colorectal cancer patients.

Design and Fabrication of Full Wheatstone-Bridge-Based Angular GMR Sensors.

Since the discovery of the giant magnetoresistive (GMR) effect, GMR sensors have gained much attention in last decades due to their high sensitivity, small size, and low cost. The full Wheatstone-bridge-based GMR sensor is most useful in terms of the application point of view. However, its manufacturing process is usually complex. In this paper, we present an efficient and concise approach to fabricate a full Wheatstone-bridge-based angular GMR sensor by depositing one GMR film stack, utilizing simple patterned processes, and a concise post-annealing procedure based on a special layout. The angular GMR sensor is of good linear performance and achieves a sensitivity of 0.112 mV/V/Oe at the annealing temperature of 260 °C in the magnetic field range from -50 to +50 Oe. This work provides a design and method for GMR-sensor manufacturing that is easy for implementation and suitable for mass production.

A High Strength Self-Healable Antibacterial and Anti-Inflammatory Supramolecular Polymer Hydrogel.

There is a significant cost to mitigate the infection and inflammation associated with the implantable medical devices. The development of effective antibacterial and anti-inflammatory biomaterials with novel mechanism of action has become an urgent task. In this study, a supramolecular polymer hydrogel is synthesized by the copolymerization of N-acryloyl glycinamide and 1-vinyl-1,2,4-triazole in the absence of any chemical crosslinker. The hydrogel network is crosslinked through the hydrogen bond interactions between dual amide motifs in the side chain of N-acryloyl glycinamide. The prepared hydrogels demonstrate excellent mechanical properties-high tensile strength (≈1.2 MPa), large stretchability (≈1300%), and outstanding compressive strength (≈11 MPa) at swelling equilibrium state. A simulation study elaborates the changes of hydrogen bond interactions when 1-vinyl-1,2,4-triazole is introduced into the gel network. It is demonstrated that the introduction of 1-vinyl-1,2,4-triazole endowes the supramolecular hydrogels with self-repairability, thermoplasticity, and reprocessability over a lower temperature range for 3D printing of different shapes and patterns under simplified thermomelting extrusion condition. In addition, these hydrogels exhibit antimicrobial and anti-inflammatory activities, and in vitro cytotoxicity assay and histological staining following in vivo implantation confirm the biocompatibility of the hydrogel. These hydrogels with integrated multifunctions hold promising potential as an injectable biomaterial for treating degenerated soft supporting tissues.