Effect Of Treatment Research Articles

Six year cumulative treatment effect of MiSight® 1 day: A dual focus myopia control contact lens

Six year cumulative treatment effect of MiSight® 1 day: A dual focus myopia control contact lens

The treatment effect across ASPECTS in acute ischemic stroke: Analysis from the AcT Trial.

Early ischemic changes on baseline imaging are commonly evaluated for acute stroke decision-making and prognostication. We assess the association of early ischemic changes on clinical outcomes and whether it differs between intravenous tenecteplase versus Alteplase. Data are from the phase 3, Alteplase compared to Tenecteplase (AcT) trial. Subjects with anterior circulation stroke were included. Early ischemic changes were assessed using the Alberta Stroke Program Early CT score (ASPECTS). Efficacy outcomes included modified Rankin scale (mRS) 0-1, mRS 0-2, and ordinal mRS at 90 days. Safety outcomes included 24-hour symptomatic intracerebral hemorrhage (sICH), any hemorrhage on follow-up scan, and 90-day mortality rate. Mixed effects logistic regression was used to assess the association of ASPECTS [continuous and categorical (0-4 vs. 5-7 vs. 8-10)] with outcomes and if these associations were modified by thrombolytic type after adjusting for age, sex, and baseline stroke severity. Of the 1577 patients in the trial, 901 patients (56.3%) (median age 75 years [IQR 65-84], 50.8% females, median NIHSS 14 [IQR 17-19]) with anterior circulation stroke were included. mRS 0-1 at 90d was achieved in 1/14 (0.3%), 43/160 (14.7%) and 252/726 (85.1%) in the ASPECTS 0-4, 5-7 and 8-10 groups respectively. Every 1-point decrease in ASPECTS was associated with 2.7% and 1.9% decrease in chances of mRS 0-1 and mRS 0-2 at 90 days, respectively, and 1.9% chances of increase in mortality at 90 days. Subgroup analysis in EVT treated population showed similar results. Thrombolytic type did not modify this association between ASPECTS and 90-day mRS 0-1 (P interaction 0.75). There was no significant interaction by thrombolytic type with any other outcome. Similar to prior studies, we found that every one-point decrease in ASPECTS was associated with poorer clinical and safety outcomes. This effect did not differ between alteplase and tenecteplase.

Prognostic Factors Related to Sleep Quality in Patients With Obstructive Sleep Apnea After Positive Airway Pressure Therapy

Background and Objectives: This study aimed to evaluate the factors that influence deep sleep restoration in patients with obstructive sleep apnea (OSA) following positive airway pressure (PAP) therapy.Methods: In total, 363 patients diagnosed with OSA who received PAP therapy over at least 3 months were enrolled in the study. Polysomnographic parameters, anatomical characteristics, and subjective sleep-related parameters were evaluated according to the presence of daytime sleepiness and morning headache before and after 3 months of PAP treatment.Results: Age was significantly different according to whether excessive daytime sleepiness (EDS) was alleviated (average: 49.35 years) or persisted (average: 52.82 years) (p=0.001). Age was also significantly associated with morning headache (p=0.037). Body mass index (BMI) was higher in the alleviated EDS group (28.70 kg/m<sup>2</sup>) than in the persistent EDS group (27.13 kg/m<sup>2</sup>; p=0.002). The apnea-hypopnea index (AHI) was correlated with the EDS outcome (p=0.011). The group with alleviated EDS had a longer mandibular plane to hyoid distance (MPH) than the group with persistent EDS (17.95 mm vs. 15.38 mm; p<0.001). However, BMI, AHI, and MPH showed no significant associations with morning headache. Epworth Sleepiness Scale scores were higher in the alleviated EDS and alleviated morning headache groups (EDS: p<0.001, morning headache: p=0.001). Self-Efficacy Measure for Sleep Apnea (SEMSA) values differed significantly between the EDS groups (p<0.001), but not between the morning headache groups (p=0.122). After 3 months of PAP therapy, the MPH was negatively correlated with EDS in univariate (odds ratio [OR]=0.921, p<0.001) and multivariate analyses (OR=0.937, p=0.028). The SEMSA score was also negatively correlated with EDS in univariate (OR=0.961, p<0.001) and multivariate (OR=0.973, p=0.019) analyses.Conclusion: Age, polysomnographic metrics, and anatomical considerations were important for sleep quality-associated daytime symptoms. In addition, anatomical characteristics and the patient’s self-efficacy were significantly associated with the effect of PAP treatment on sleep quality.

Anti-inflammatory effect of the combined treatment of LMT-28 and kaempferol in a collagen-induced arthritis mouse model.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by joint inflammation and swelling. Several studies have demonstrated that RA fibroblast-like synovial cells (RA-FLS) play an important role in RA pathogenesis. Activated RA-FLS contribute to synovial inflammation by secreting inflammatory cytokines including interleukin (IL)-1β, IL-6 and tumor necrosis factor-α. LMT-28 is derivative of oxazolidone and exerts anti-inflammatory effects on RA via IL-6 signaling pathway regulation. LMT-28 also regulates T cell differentiation in RA condition. However, the effect of LMT-28 on the migration and invasion of RA-FLS remains unknown. Kaempferol has been reported to have pharmacological effects on various diseases, such as inflammatory diseases, autoimmune diseases, and cancer. Additionally, kaempferol has been reported to inhibit RA-FLS migration and invasion, but it is not known about the therapeutic mechanism including molecular mechanism such as receptor. The present study aimed to investigate the synergistic effects of the combined treatment of LMT-28 and kaempferol on RA-FLS activation and RA pathogenesis in mouse model. LMT-28 and kaempferol co-administration inhibited RA disease severity and histological collapse in the joint tissues of CIA mice, as well as downregulated the levels of pro-inflammatory cytokines in mouse serum. Additionally, the combined treatment inhibited excessive differentiation of T helper 17 cells and osteoclasts. Furthermore, compared with single treatments, combined treatment showed enhanced inhibitory effects on the hyperactivation of IL-6-induced signaling pathway in RA-FLS. Combined treatment also inhibited RA-FLS cell proliferation, migration, and invasion and suppressed the expression of matrix metalloproteinase in RA-FLS. Furthermore, we confirmed that the combined treatment inhibited chondrocyte proliferation, migration, and invasion. In conclusion, our results suggest that the combined treatment of LMT-28 and kaempferol exerts a synergistic effect on the RA development via the regulation of IL-6-induced hyperactivation of RA-FLS. Furthermore, this study suggests that combination therapies can be an effective therapeutic option for arthritis.

Investigations on structure and properties of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) reinforced by diss fibers: Effect of various surface treatments

The paper reports some experimental results on the effect of different chemical modifications of Diss fibers on the properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) biocomposites involving alkaline, combined alkaline/peroxide and combined alkaline/silane treatments. The biocomposite samples loaded at 20 wt% were prepared by melt compounding. Scanning Electron Microscopy (SEM) showed a better fiber-matrix interaction between Diss fiber and matrix after surface fiber treatment. Differential Scanning Calorimetry (DSC) and X-ray Diffraction (XRD) results indicated an increase in crystallinity index of the biocomposites. In addition, the incorporation of Diss fibers treated with alkali-silane resulted in an improvement in Heat Deflection Temperature (HDT) and shore D hardness from 141.1 °C and 75.1–145.7°C and 86.2, respectively, in comparison with the neat matrix. This also agreed with the flexural properties results, which showed a significant increase in flexural modulus by almost 30 % compared to the neat PHBV. The same trend was observed for water absorption. Overall, combined alkali-silane treatment was found to be most efficient surface treatment method to develop strong interfacial adhesion between PHBV and Diss fiber, increasing the scope of application in manufacturing of light weight green composites.

THE EFFECT OF STEM INTEGRATED PROBLEM-BASED LEARNING MODEL (PBL) ON STUDENTS’ LEARNING OUTCOMES ON HUMAN RESPIRATORY AND EXCRETION SYSTEM

Learning at UPT SMPN 1 Sutera seems to be still low, this is because the learning model used by teachers is still not appropriate and the discussion process has not been carried out well. One way to overcome this problem is to apply the STEM integrated Problem-Based Learning (PBL) model. This research aims to determine the effect of the STEM integrated Problem-Based Learning (PBL) model on student learning outcomes in human respiratory and excretory system material at UPT SMPN 1 Sutera. The type of research used in the research is Quasi Experiment, namely a research method to find the effect of certain treatments on others under controlled conditions. The design used in this research is the Non-Equivalent Control Group Design. The population in this study were class VIII students at UPT SMPN 1 Sutera. The sample in this study consisted of two classes, namely the experimental class and the control class which were taken using a purposive sampling technique. The instruments used consisted of an observation sheet on the implementation of the STEM integrated PBL model, pre-test and post-test questions. The research data obtained was then analyzed through descriptive statistical tests and inferential statistics using SPSS version 25. Based on the results of the analysis in hypothesis testing, it showed that there was a significant average difference between the control and experimental classes. The results of research hypothesis testing were found to be 0.000 and smaller than 0.05. Thus, it can be seen that the significant difference between Ha is accepted and H0 is rejected, so there is an influence. The conclusion from the hypothesis test is that there is a significant influence between students' scores using the STEM integrated PBL learning model. So H0 is rejected and Ha is accepted. So there is an influence of the STEM integrated PBL model on student learning outcomes.

The contemporary issues related to conventional treatment of acne and the way forward

Background: People perceive acne as a minority disorder (not a major health concern), but it has a significant impact and burden on the victims. Although conventional drugs are available for its treatment, which are applied directly to the affected skin, such as azelaic acid, benzoyl peroxide, and salicylic acid etc. or formulationAcne vulgaris is a common skin condition that can have a significant impact on individuals, yet conventional treatments often come with various contemporary issues. This paper discusses the contemporary issues related to the conventional treatment of acne and explores a way forward. Acne vulgaris is a chronic inflammatory disorder of the pilosebaceous unit, with a high prevalence globally and in Nigeria. Although conventional drugs are available for treatment, there are several contemporary issues related to their usage that need to be addressed. Method: Relevant literature, including stakeholder reports and studies conducted globally and locally, were searched and reviewed to identify the contemporary issues related to conventional acne treatment. The key contemporary issues identified include economic, environmental, emotional, social, and spiritual concerns. Findings: The economic burden of costly conventional medications makes them inaccessible for many. Environmental issues arise from the use of potentially harmful chemicals that can pollute water sources and contribute to climate change. Acne can also lead to emotional distress, social stigma, and spiritual conflicts, especially due to the side effects of conventional treatments. Given the limitations of conventional treatments, the article recommends the use of scientifically-proven herbal remedies as a promising alternative strategy. Herbs such as tea tree oil, green tea, chasteberry, black seed, and spikeweed have demonstrated antibacterial, anti-inflammatory, and anti-androgenic properties that can effectively manage acne without the adverse effects of conventional drugs. Conclusion: The use of evidence-based herbal medicines offers a way forward in the treatment of acne, addressing the contemporary issues associated with conventional approaches. Further clinical research and regulatory approval are necessary to integrate these herbal remedies into conventional acne management and ensure their widespread and safe use. Novelty/Originality of this article: This study proposes an integrated acne treatment framework that combines conventional therapies with evidence-based herbal medicine. This approach addresses contemporary issues in acne treatment by considering economic, environmental, and socio-cultural aspects.

Resveratrol reversed rosiglitazone administration induced bone loss in rats with type 2 diabetes mellitus

Rosiglitazone (RSG), as an insulin-sensitizing drug to treat type 2 diabetes mellitus (T2DM) is reported to decrease bone quality and increase bone fracture risk. The multiple off-target effects of Resveratrol (RSV), a natural specific agonist of Sirtuin1 (Sirt1) with pro-osteoblastogenesis and anti-adipogenesis effects, on bone loss in T2DM are still under discussion. In this study, successfully ovariectomized rats were fed with high-fat diet and STZ (HFD/STZ) to induced T2DM mice. RSV alone, RSG alone or co-administration of RSV and RSG were given orally to T2DM rats for 8 weeks to determine whether RSV administration had any prevention effect on T2DM osteoporosis. Bone mesenchymal stem cells (BMSCs) and bone marrow‑derived macrophages (BMMs) were cultured under high glucose condition and were induced to osteoblasts or adipocytes and osteoclasts, respectively. μCT and HE staining showed that in T2DM osteoporotic rats, RSV co-administration prevents RSG induced-bone loss. ELISA results confirmed that RSV suppressed osteoclast activity and promoted osteoblast activity in diabetic osteoporosis rats and RSG-administrated diabetic osteoporosis rats. In vitro study showed that RSV significantly reversed RSG induced inhibition on osteogenesis and promotion on adiopogenesis of BMSC under high glucose (HG). Moreover, RSV significantly reverse RSG induced osteoclast formation and mature under HG. Taken together, these findings uncover a previously unappreciated anti-osteoporosis effect of concomitant treatment with RSV in RSG-administrated diabetic rats, suggesting the clinical use of RSV as an adjuvant in the treatment of T2DM for preventing or reversing RSG administration-associated bone loss.

Perioperative Metformin Treatment to Reduce Postoperative Hyperglycemia After Colon Cancer Surgery: A Randomized Clinical Trial.

Surgery induces a stress response causing insulin resistance that may result in postoperative hyperglycemia. Postoperative hyperglycemia is associated with increased incidence of complications, longer hospitalization and greater mortality. This study examined the effect of metformin treatment on the percentage of patients experiencing postoperative hyperglycemia after elective colon cancer surgery. This was a randomized double-blind placebo-controlled trial. The study was conducted at Slagelse Hospital, Slagelse, Denmark. Patients without diabetes planned for elective surgery for colon cancer were included. Patients received metformin 500mg three times a day or placebo for 20 days before and 10 days after surgery. Blood glucose levels were measured several times daily until the end of postoperative day two. The main outcome measures were the percentage of patients who experienced at least one blood glucose measurement above 7.7 and 10 mmol/l, respectively. Rates of complications within 30 days of surgery and Quality of recovery-15 scores were also recorded. Of the 48 included patients, 21 (84.0%) in the placebo group and 18 (78.3%) in the metformin group had at least one blood glucose measurement above 7.7 mmol/l (p = 0.72), and 13 (52.0%) patients in the placebo group had a measurement above 10.0 mmol/l versus 5 (21.7%) in the metformin group, (p = 0.04). No differences in complication rates or Quality of recovery-15 scores were seen. The number of patients in the study was too low to detect a possible difference in postoperative complications. Blood glucose was measured as spot measurements instead of continuous surveillance. In patients without diabetes, metformin significantly reduced the percentage of patients experiencing postoperative hyperglycemia as defined as spot blood glucose measurements above 10 mmol/l after elective colon cancer surgery. See Video Abstract.

Investigation of the effect of relative humidity on micro lime consolidation of degraded earthen structures

Micro lime, hydrated lime (Ca (OH)2) with particle sizes of 1-3μ dispersed in isopropanol, can be used to reinforce deteriorated earthen structures. The consolidation effect depends on the amount of moisture present in the structure or in the ambient air. This study investigates the influence of different levels of relative humidity (RH) on the consolidation effect of micro lime on earthen structures, the chemical processes responsible for the consolidation and the physical changes to the structure. The aim is to gain a deeper understanding of the underlying chemical reactions and to identify a potential limit to the applicability of this consolidation method in low RH environments. The fact that many of these sites are located in arid climates greatly influences the practical application of micro lime in the conservation of historical earthen structures. To characterize the consolidation effect of micro lime, unconfined compressive strength and exposure to wet and dry cycles were used. The properties of the reaction products and the bonding between soil particles and micro lime were investigated using thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM). At RH levels of 25%, 45%, 65% and 90%, the unconfined compressive strength (UCS) and the modulus of deformation at 50% strength (E50) of the micro lime-reinforced specimens demonstrated an increase with humidity. This led to a significant improvement in their ability to resist the effects of dry–wet cycles. Results from thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) indicate that micro lime interacts with the soil matrix via carbonation, with the reaction rate increasing with humidity. At 25% RH, vaterite was produced and residual free lime was observed, whereas at humidity levels of 45% and above, the reaction yielded vaterite and aragonite. The lime treatment did not significantly alter the pore structure of the soil specimens. The total porosity of the specimens was only slightly reduced, with the main effect of the lime treatment being a reduction in the number of large pores.

Effects of several long-term soil health treatments on populations of Pratylenchus penetrans and the soil microbial community

AbstractSoil suppressiveness can reduce the damage by plant parasitic nematodes (PPN) in agricultural soils and is conveyed by the activity of soil microorganisms. While natural suppressiveness has been reported, it is still poorly understood if soil suppressiveness can be elicited by manipulating the soil microbial community. In the present study we assessed the number of the Pratylenchus penetrans (Pp) and the bacterial and fungal community composition over 7 years in a long-term soil health experiment. The field experiment consisted of an organic and conventional agricultural land management system and three soil health treatments (SHT): an untreated control (CT), anaerobic disinfestation (AD) and a combination of marigold cover cropping, compost and chitin amendment (CB). The land management systems were kept continuously, while the soil health treatments were applied only twice in seven years. The microbial community significantly differed between the organic and conventional system, but there was no significant difference in Pp numbers between the two systems. However, both the CB treatment and to a lesser extent the AD treatment reduced Pp numbers and increased yield with the effect being the strongest in the years immediately after the treatment. Accordingly, both the bacterial and fungal community differed significantly between the treatments, the differences being largest in the years after the treatments. Notably, the CB treatment elicited both long-term changes in the microbial community and a reduction of Pp numbers lasting for at least three years. These results indicated that a combination of treatments can lead to an altered soil microbial community in combination with persisting suppressiveness of Pp.

Heat treatments effects on Wear performance of Laser based Powder Bed Fusion fabricated Inconel 718 alloy

Among the AM processes Laser based Powder Bed Fusion (LPBF) technique offers precise and complex geometric fabrication. However, the microstructural and mechanical properties obtained from LPBF process requires further investigation, especially for IN718 superalloys. In this study, various heat treatments were applied to LPBFed Inconel 718 specimens to examine their effects on microstructure, microhardness and wear behavior. Three different heat treatments, each involving varied solutionizing and ageing steps were incorporated. As-printed specimens exhibited distinct fish scale structures with columnar dendrites. Heat treatments effectively dissolved the Laves phase and precipitated strengthening phases like γ′′ and γ′. Microhardness increased significantly after heat treatments, correlating with the formation of strengthening precipitates. Friction and wear tests showed as-printed specimens exhibited higher wear loss (922 ± 13 μm) and coefficient of friction (COF) (0.511 ± 0.07) due to the presence of Laves phase and softer matrix. Heat-treated specimens demonstrated significantly reduced wear loss (262 ± 5 μm) and COF (0.368 ± 0.01), with HT2 showing the best wear resistance attributed to a homogeneous microstructure. SEM analysis of worn surfaces confirmed abrasive and adhesive wear mechanisms in as-printed specimens, while heat-treated specimens exhibited reduced wear with smoother surfaces.

The impact of heterogeneity on the analysis of platform trials with normally distributed outcomes

BackgroundA platform trial approach allows adding arms to on-going trials to speed up intervention discovery programs. A control arm remains open for recruitment in a platform trial while intervention arms may be added after the onset of the study and could be terminated early for efficacy and/or futility when early stopping is allowed. The topic of utilising non-concurrent control data in the analysis of platform trials has been explored and discussed extensively. A less familiar issue is the presence of heterogeneity, which may exist for example due to modification of enrolment criteria and recruitment strategy.MethodWe conduct a simulation study to explore the impact of heterogeneity on the analysis of a two-stage platform trial design. We consider heterogeneity in treatment effects and heteroscedasticity in outcome data across stages for a normally distributed endpoint. We examine the performance of some hypothesis testing procedures and modelling strategies. The use of non-concurrent control data is also considered accordingly. Alongside standard regression analysis, we examine the performance of a novel method that was known as the pairwise trials analysis. It is similar to a network meta-analysis approach but adjusts for treatment comparisons instead of individual studies using fixed effects.ResultsSeveral testing strategies with concurrent control data seem to control the type I error rate at the required level when there is heteroscedasticity in outcome data across stages and/or a random cohort effect. The main parameter of treatment effects in some analysis models correspond to overall treatment effects weighted by stage wise sample sizes; while others correspond to the effect observed within a single stage. The characteristics of the estimates are not affected significantly by the presence of a random cohort effect and/ or heteroscedasticity.ConclusionIn view of heterogeneity in treatment effect across stages, the specification of null hypotheses in platform trials may need to be more subtle. We suggest employing testing procedure of adaptive design as opposed to testing the statistics from regression models; comparing the estimates from the pairwise trials analysis method and the regression model with interaction terms may indicate if heterogeneity is negligible.

Hypofractionated stereotactic radiotherapy for brain metastases in lung cancer patients: dose‒response effect and toxicity

BackgroundLung cancer is a common cause of brain metastases, approximately 40% of patients with lung cancer will develop brain metastases at some point during their disease. Hypofractionated stereotactic radiotherapy (HSRT) has been demonstrated to be effective in controlling limited brain metastases. However, there is still no conclusive on the optimal segmentation of HSRT. The aim of our study was to explore the correlation between the HSRT dosage and its treatment effect and toxicity.MethodsA retrospective analysis was conducted on patients with non-small cell lung cancer (NSCLC) brain metastasis at Hangzhou Cancer Hospital from 1 January 2019 to 1 January 2021. The number of brain metastases did not exceed 10 in all patients and the number of fractions of HSRT was 5. The prescription dose ranges from 25 to 40 Gy. The Kaplan–Meier method was used for estimation of the localised intracranial control rate (iLC). Adverse radiation effects (AREs) were evaluated according to CTCAE 5.0. This study was approved by the Institutional Ethics Review Board of the Hangzhou Cancer Hospital (#73/HZCH-2022).ResultsForty eligible patients with a total of 70 brain metastases were included in this study. The 1-year iLC was 76% and 89% in the prescribed dose ≤ 30 Gy and > 30 Gy group, respectively (P < 0.05). For patients treated with HSRT combined with targeted therapy, immunotherapy and chemotherapy, the 1-year iLC was 89%, 100%, and 45%, respectively. No significant associations were observed between the number, maximum diameter, location, and type of pathology of brain metastases. The rate of all-grade AREs was 33%. Two patients who received a total dose of 40 Gy developed grade 3 headache, the rest of the AREs were grade 1–2.ConclusionsIncreasing the prescription dose of HSRT improves treatment effect but may also exacerbate the side effects. Systemic therapy might impact the iLC rate, and individualized treatment regimens need to be developed.

Association of rheumatoid factor, anti-citrullinated protein antibodies and shared epitope with clinical response to initial treatment in patients with early rheumatoid arthritis: data from a randomised controlled trial

ObjectivesTo investigate whether rheumatoid factor (RF), anti-citrullinated protein antibodies (ACPAs) and shared epitope (SE) allele-related genetic markers associate with treatment response to abatacept, certolizumab pegol or tocilizumab versus active conventional...

Severe weight loss during PD-1 treatment is a risk sign of poor prognosis for advanced GC patients.

To verify whether severe weight loss is a reasonable risk sign for the effect of PD-1 treatment in advanced gastric cancer (GC) patients. 127 metastatic or recurrent GC patients treated with PD-1 inhibitors in Xuzhou Central Hospital were involved in this study. Two cohorts with different variables were built; one was used to reveal the relationship between body weight loss and overall survival (OS), and the other was used to find which body composition contributed to the weight loss. Variables were collected at PD-1 inhibitor initiation (baseline) and week 6 of treatment. Patients were followed up from the end of therapy to November 2022. Overall survival(OS) and disease-free survival (DFS) were recorded. 127 patients with metastatic/recurrent gastric cancer received PD-1 treatment, among whom 117 had complete weight data. After screening, data from 69 patients were used for body composition assessment. The study found that 33 patients who lost more than 2% of their body weight within six weeks had poorer OS and DFS, with medians of 9.5months and 6months, respectively. Cox regression analysis showed that weight loss of more than 2% and treatment methods was an independent risk for poor OS and DFS. Further analysis revealed that weight loss was mainly caused by a reduction in adipose tissue, rather than muscle mass. Severe weight loss is a potential monitor for the treatment effect of PD-1 inhibitor in advanced GC patients.

How estimating nuisance parameters can reduce the variance (with consistent variance estimation).

We often estimate a parameter of interest when the identifying conditions involve a finite-dimensional nuisance parameter . Examples from causal inference are inverse probability weighting, marginal structural models and structural nested models, which all lead to unbiased estimating equations. This article presents a consistent sandwich estimator for the variance of estimators that solve unbiased estimating equations including which is also estimated by solving unbiased estimating equations. This article presents four additional results for settings where solves (partial) score equations and does not depend on . This includes many causal inference settings where describes the treatment probabilities, missing data settings where describes the missingness probabilities, and measurement error settings where describes the error distribution. These four additional results are: (1) Counter-intuitively, the asymptotic variance of is typically smaller when is estimated. (2) If estimating is ignored, the sandwich estimator for the variance of is conservative. (3) A consistent sandwich estimator for the variance of . (4) If with the true plugged in is efficient, the asymptotic variance of does not depend on whether is estimated. To illustrate we use observational data to calculate confidence intervals for (1) the effect of cazavi versus colistin on bacterial infections and (2) how the effect of antiretroviral treatment depends on its initiation time in HIV-infected patients.

Effect of precipitation hardening on the microstructure, mechanical, and corrosion properties of additively manufactured A20X aluminum alloy

The effect of age hardening treatment on microstructure, tensile properties, and corrosion behavior of additively manufactured A20X alloy was investigated. Three single-step aging temperatures (150 °C, 175 °C, and 200 °C) and one double-step aging temperature (pre-aging at 165 °C followed by aging at 185 °C) along with varying heat treatment durations ranging from 30 min to 144 h, were studied systematically. Microstructural characterizations revealed that the co-existence of coherent/semi-coherent (Ω, θ′) and incoherent precipitates (θ) resulted in the maximum hardening effect (up to 30 % higher microhardness). This improved the yield strength at room and 150 °C by 33.4 % and 22.6 %, respectively. Double aging delivered the best combination of microstructure with fine grains and optimal precipitate assembly in a short duration (12–16 h). The heat-treated LPBF A20X showed higher ductility and similar mechanical properties compared to the cast A20X. However, optimal precipitate characteristics reduced the corrosion potential by 13–16 % due to a higher galvanic reaction. The highest corrosion potential (−0.622 V) was achieved in the solutionized state.

The Effect of Additional Silane Pre-Treatment on the Microtensile Bond Strength of Resin-Based Composite Post-and-Core Build-Up Material

The aim of this study was to evaluate the effect of additional silane treatment on the immediate and aged microtensile bond strength (µTBS) between resin-based composite (RBC) post-and-core build-up material and an RBC CAD/CAM block. Twelve sample blocks (12 mm × 14 mm × 9 mm) were prepared using RBC post-and-core build-up material and were divided into six groups: Kerr Silane Primer (Sil) + OptiBond eXTRa Universal adhesive (EXA); OptiBond eXTRa Universal Primer (EXP) + EXA; Sil + OptiBond Universal (OBU); OBU; Sil + OptiBond Solo Plus (OSP); and OSP. Each treated sample was luted to a CAD/CAM block using an NX3 Nexus Third-Generation instrument. After storage in 37 °C water for 1 week, microspecimens were fabricated, and μTBS was tested immediately or after further immersion in water at 37 °C for 6 months. The failure mode of each specimen was determined using stereomicroscopy and scanning electron microscopy. For the immediate groups, no significant difference in µTBS was found between specimens with or without silane treatment for each adhesive (p &gt; 0.05). For the aged groups, silane treatment significantly decreased µTBS for OptiBond eXTRa Universal (p &lt; 0.05). Our findings indicate that additional silane treatment prior to the application of adhesive did not enhance µTBS.

Pedestrian and Car Occupant Crash Casualties Over a 9-Year Span of Vision Zero in New York City

Vision Zero has been increasingly embraced by jurisdictions across the United States. Existing research primarily focuses on the theoretical principles and effectiveness of specific engineering measures. However, there is limited understanding of the holistic effects of Vision Zero treatments, in the context of street type and urban environment. We developed a street typology framework to categorize street segments using four design and operational features: street width, traffic direction (one- versus two-way), number of travel lanes, and presence of on-street parking. We applied a sample-based partitioning around medoids algorithm to classify 90,327 street segments in New York City. This process results in six distinctive types of street segment. To integrate neighborhood-level factors (e.g., land use variables and sociodemographics), we aggregated street segments of a given street type for each neighborhood. Negative binomial regression models were developed for pedestrian and car occupant crash injuries and fatalities separately for three periods: 2014 to 2016, 2017 to 2019, and 2020 to 2022. Our findings showed that street-segment groups with narrower, two-way sections and greater tree canopy coverage were significantly associated with a lower risk of casualties for both pedestrians and motorized users. Street-segment groups located in neighborhoods with a larger percentage of African American and Hispanic American residents experienced a significantly greater risk of casualties. Vision Zero treatments had mixed effects on safety outcomes. Streets treated with leading pedestrian intervals showed a lower risk of casualties. Neighborhood- and arterial slow zones were associated with a lower risk of car occupant casualties.