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Background: Cervical pedicle screw-rod fixation presents a complex approach in spinal surgery, offering enhanced spine stabilization in variable conditions considering traumatic injuries, degenerative changes, as well as orthopaedic and oncological ailments. This technique employs small diameter screw implants strategically placed to bolster the mechanical integrity of the spine. Notably, it involves minimally invasive procedures, resulting in smaller incisions and reduced patient discomfort. This study aims to assess the effects of trapezoidal thread screws in pedicle sections of the cervical spine during flexion-extension loadings, focusing on factors such as range of motion (ROM), implant stress, and stress on adjacent bone. Methods: Utilizing CT scan data, a finite element model of the cervical spine (C2-C7 vertebrae) was prepared. Trapezoidal thread screws were integrated into a single-level pedicle screw-rod fixation at the C5-C6 vertebrae. The C2 vertebra were given a compressive load of 50 N along with a moment of 1 Nm, resulting in the immobilization of the C7. Results and Discussion: The results indicate a reduction in ROM at the C5-C6 level by 69% to 77% compared to the intact spine during flexion-extension loading, with a slight increase in ROM observed at adjacent cervical spine levels. Stress analysis revealed that the trapezoidal thread screws induced stresses ranging from 24 MPa to 29 MPa in PEEK trapezoidal screw-rod implants, which fall below the material's yield stress. Conclusions: This suggests that the trapezoidal thread profile may be advantageous in minimizing stress concentration, attributed to its larger contact area with the vertebrae bone between the threads. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVE: There is a paucity of pooled synthesized data on the epidemiology of neonatal acute kidney injury (AKI). Our objective with this study is to systematically assess the worldwide incidence of AKI in neonates. METHODS: We searched 3 electronic databases (Embase, PubMed, Web of Sciences) from January 2004 to December 2022 without language restrictions. We included cohort and cross-sectional studies that reported the incidence of AKI or associated mortality in neonates. Eligible studies had at least 10 participants and used standard criteria (Acute Kidney Injury Network/Pediatric Risk, Injury, Failure, Loss, End Stage Renal Disease (pRIFLE)/ Kidney Disease Improving Global Outcomes) to define AKI. Two authors independently retrieved data on demographic characteristics, clinical setting, and outcomes (incidence and AKI-associated mortality) using a semi-structured proforma and assessed the risk of bias. We used a random-effects metaanalysis to calculate pooled estimates with 95% confidence intervals. RESULTS: We included 201 studies (98 228 participants) from 45 countries. The incidence of any stage AKI was 30% (95% confidence interval 28-32), and that of severe AKI was 15% (14-16). Overall, AKI-associated mortality was 30% (27-33). The odds of mortality were higher (odds ratio 3.4; 2.9-4.0) in neonates with AKI compared with those without AKI. We found that perinatal asphyxia, sepsis, patent ductus arteriosus, necrotizing enterocolitis, and nephrotoxic medications were significant risk factors for AKI. Significant heterogeneity in the pooled estimates was a limitation of this study. CONCLUSIONS: AKI was observed in one-third of the neonates and was associated with increased risk of mortality. The incidence of AKI was almost similar in neonates with perinatal asphyxia and sepsis, but mortality was higher in the former group. [ABSTRACT FROM AUTHOR]

Background: Several observational studies have reported the prevalence of cerebral microbleeds (CMBs) and their risk factors in an elderly population. Any information in this regard is currently lacking from India. Aim of this study was to estimate the prevalence, risk factors of CMBs, and association with cognition in an Indian urban population aged 50 years and above. Methods: Household surveys were conducted as part of ongoing Longitudinal Cognition and Aging Research on Population of the National Capital Region (LoCARPoN) study in areas of urban Delhi. Magnetic resonance imaging of the brain was performed in 2599 participants. Using standard neuropsychological battery, mean Z-scores for each domain (memory, executive, information) were derived. Binary and stepwise logistic regression models were used to determine associated risk factors for the presence of CMB and its association with cognitive domains. Results: The prevalence of CMBs was 14.42% (95% confidence interval [CI]: 13.06-15.73). Of these, 203 (7.81%) participants had single CMBs and 172 (6.61%) had multiple microbleeds (≥2). Higher prevalence was observed in older age (6070 years: odds ratio [OR]: 1.25 [95% CI: 0.93-1.67]; 70-80 years: OR: 2.05 [95% CI: 1.48-2.84]; ≥80 years: OR: 3.27 [95% CI: 1.97-5.44]) compared to individuals in the age group 50-60 years. History of stroke (OR: 2.97 [95% CI: 1.56-5.66]), hypertension (OR: 1.36 [95% CI: 1.05-1.75]), and smoking (OR: 1.43 [95% CI: 1.11-1.85]) was associated with at least one CMB. Multiple CMBs were associated with worse scores in memory and executive domains. Conclusion: Older age, hypertension, history of stroke, and history of smoking emerged as important risk factors for the presence of multiple CMBs. Follow-up study is required to determine implications of CMBs. [ABSTRACT FROM AUTHOR]

Titanium alloys are most suitable for lightweight armour applications due to their superior strength to weight ratio, and α+β Ti alloy Ti–6Al–4V is widely used in armour applications. One of the critical factors limiting the widespread use of Ti alloys in armour application is their high cost. Recently, Allegheny Technologies Incorporated introduced ATI-425® Ti alloy with the chemical composition of Ti–4Al-2.5V-1.5Fe-0.25O as a low-cost alternative to Ti–6Al–4V. Though ATI-425 Ti alloy is primarily intended for armour applications, only limited ballistic results are available in the open literature. In the present work, we compare the quasi-static, dynamic deformation, ballistic impact response and post-deformation microstructure of a low-cost α+β Ti alloy ATI-425 with that of Ti–6Al–4V alloy. Analysis of the results showed that both alloys showed similar yield strength values during quasi-static tension and compression tests, while ATI-425 Ti alloy showed higher tensile ductility, Charpy-V notch impact energy and dynamic flow stress than Ti-6Al-4V. The ATI-425 Ti alloy also exhibited slightly better ballistic performance measured in terms of V 50 ballistic limit velocity. Detailed microstructural analysis on quasi-static and dynamic compression-tested samples showed mainly {10 1 – 2} tensile twins, whereas {10 1 – 2} and {11 2 – 1} tensile twins are observed in ballistic-tested samples of both the alloys. Activation of deformation twinning in ATI-425 Ti alloy with higher oxygen is attributed to lower Al content which enhances the twinning activity. Adiabatic shear band (ASB)-induced plugging mechanism is ascertained as the perforation mode in both alloys during the ballistic impact. Analysis of propensity to ASB formation indicated that Ti-6Al-4V has a slightly better resistance to ASB formation than ATI-425 Ti alloy. The improved ballistic performance of ATI-425 Ti alloy in comparison to Ti-6Al-4V is attributed to the higher dynamic flow stress, Charpy-V notch impact energy absorption, and moderate resistance to adiabatic shear band formation. • Quasi-static, dynamic deformation, and ballistic impact response of ATI-425 and Ti–6Al–4V alloys studied. • Both alloys showed similar yield strength during quasi-static tension and compression tests. • ATI-425 showed higher dynamic flow stress , quasi-static ductility, CVN impact energy, and ballistic performance than Ti–6Al–4V. • Both ATI-425 and Ti-6Al-4V alloys showed deformation twinning during compression and ballistic tests. • Deformation twinning in ATI-425 with higher oxygen is attributed to lower Al content. [ABSTRACT FROM AUTHOR]