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Additive manufacturing (AM) technology has garnered significant attention for its ability to fabricate three-dimensional (3D) products with complex geometries. While continuous wave (CW) lasers have traditionally been used in AM as heat sources, they face limitations in nano and micro-scale fabrication due to the diffusion of thermal energy, which results in heat-affected zones, residual stress, substrate degradation, poor dimensional accuracy, and surface finish issues. To address these challenges, ultra-short pulse lasers, such as femto- and pico-second lasers, have proven effective at micro- and nanometer scales. The ultra-short laser pulses inhibit thermally induced mechanisms, instead generating a dense photo-excited plasma that weakens lattice cohesion, introduces disorder, and increases the mobility of atoms and defects which leads to non-thermal melting, phase transformations, and mechanical effects like Coulomb explosion, along with polymerization via two-photon excitation. These phenomena enhance AM by reducing residual stress, limiting oxidation, minimizing substrate damage, and achieving high dimensional accuracy. Ultra-short pulse lasers have enabled advancements in laser-induced nano-joining, laser powder bed fusion, direct laser writing including laser-induced transfer (LIT), and laser-induced reduction processes (LIR), two-photon polymerization (2PP), marking significant progress in the fabrication of 3D and potentially 4D products. This study reviews ultrafast laser-matter interactions, nano-joining mechanisms, and large-scale sintering processes, highlighting recent developments in selective laser melting for lightweight alloys, refractory metals, and ceramics. Direct laser writing techniques, including 2PP, LIR, and LIT, are also discussed for their role in creating complex microdevices. The paper concludes with insights into future trends and potential advancements in ultra-short-pulsed laser-based AM, emphasizing its role in driving innovation such 4D fabrication and addressing limitations like temperature estimation in non-thermal region for further improvement.

Unlocking new dimensions in wearable sensor technology, this research highlights ultrasensitive stretchable strain sensors fabricated with the customized laser-induced graphene (LIG) decorated with uniformly distributed nickel nanoparticles with a fiber laser writing process. The nickel nanoparticle-incorporated LIG (Ni-NPs@LIG) strain sensors fabricated by a simple all-laser-based method utilize a commercial fiber laser. The Ni-NPs@LIG sensors showcase an impressive gauge factor, reaching up to 248 for strain values below 5%, demonstrating a sensitivity increase of up to 430% compared to the pure LIG sensors. Moreover, these sensors offer adjustable strain sensitivity based on laser fluence. The key advancement of this study lies in the direct laser writing of highly porous nickel–graphene nanostructures with adjustable properties, making them applicable across a broad range of applications. As an application demonstration, the strain sensors were employed to assess the small deformation of a pouch battery or track the large deformation of a balloon surface.

AimThe aim of this article was to review the current clinical application of computer-aided design/computer-aided manufacturing (CAD/CAM) and three-dimensional (3D) printed dentures in dental clinics.

Background: The novel coronavirus (COVID-19) was first reported in Wuhan,China, and has since then spread worldwide, resulting in a large number of hospitalizationsand deaths. To the best of our knowledge, the study about the mental health status (depression,anxiety, and stress) among high school students during COVID-19 has not been performedin Iran. Objective: This study was performed to investigate rates of anxiety, depression, and stressamong high school students during the pandemic of COVID-19. Methods: This cross-sectional study was performed among high school students (12-18years) from 30 April until 1 June 2020, in Hamadan City, west of Iran. In total, 2852 studentscontributed to the present study. Depression Anxiety and Stress Scale 21 (DASS-21)was used in this study. Statistical analyses were conducted in STATA 14 with a significantlevel of 0.05. Results: The present study showed that although stress status was normal among most highschool students (70.3%), the status of anxiety and depression was high. The boys had reporteda higher proportion of normal status of depression (51.62% vs. 44.97%), anxiety(31.71% vs. 26.91%), and stress (77.66% vs. 66.10%) compared to the girls. Also, studentsin grades 7-9 had reported a higher percentage of normal status in all three dimensions ofstress, anxiety, and depression. Conclusion: These findings suggest that as rates of depression and anxiety are high, schoolagechildren may benefit from policymakers and other authorities active role.

•Maternal colonisation by ESBL-producing Enterobacteriaceae(ESBL-E) was reviewed.•Pooled prevalence (95% CI) of maternal colonisation by ESBL-E was 8% (95% CI, 5 to 10%) worldwide.•Pooled prevalence of ESBL-E was highest in Africa (15%, 5% to 24%).•Pooled prevalence was 6% (4% to 10%) in South America, 5% (4% to 6%) in Asia, and 4% (2% to 5%) in Europe.

At external beam radiotherapy for some tumors located at thorax region due to lack of information in gray scale fluoroscopic images tumor position determination is problematic. One of the clinical strategies is to implant clip as internal fiducial marker inside or near tumor to represent tumor position while the contrast of implanted clip is highly observable rather than tumor. As alternative, using natural anatomical landmarks located at thorax region of patient body is proposed to extract tumor position information without implanting clips that is invasive method with possible side effect. Among natural landmarks, ribs of rib-cage structure that result proper visualization at X-ray images may be optimal as representative for tumor motion. In this study, we investigated the existence of possible correlation between ribs as natural anatomical landmarks and various lung and liver tumors located at different sites as challenging issue. A simulation study was performed using data extracted from 4-dimensional extended cardiac-torso anthropomorphic phantom that is able to simulate motion effect of dynamic organs, as well. Several tumor sites with predefined distances originated from chosen ribs at anterior–posterior direction were simulated at 3 upper, middle, and lower parts of chest. Correlation coefficient between ribs and tumors was calculated to investigate the robustness of ribs as anatomical landmarks for tumor motion tracking. Moreover, a consistent correlation model was taken into account to track tumor motion with a rib as best candidate among selected ribs. Final results represent availability of using rib cage as anatomical landmark to track lung and liver tumors in a noninvasive way. Observations of our calculations showed a proper correlation between tumors and ribs while the degree of this correlation is changing depends on tumor site while lung tumors are more varied and complex with less correlation with ribs motion against liver tumors.

The Shahroud fault system is a major active structure in the Alborz range of NE Iran whose slip rate is not well constrained despite its potential high seismic hazard. In order to constrain the slip rate of the eastern Shahroud fault zone, we use space‐borne synthetic aperture radar interferometry with both ascending and descending Envisat data to determine the rate of interseismic strain accumulation across the system. We invert the slip rate from surface velocity measurements using a half‐space elastic dislocation model. The modeling results are consistent with a left‐lateral slip rate of 4.75 ± 0.8 mm/yr on the Abr and Jajarm, strands of the Shahroud fault, with a 10 ± 4 km locking depth. This is in good agreement with the 4–6 mm/yr of left‐lateral displacement rate accumulated across the total Shahroud fault system obtained from GPS measurements. We find fast slip rate of 4–5 for Shahroud fault based on modeling of InSAR dataThe 5 mm of slip rate is absorbed on the Abr and Jajarm strands of Shahroud faultThe new information provides useful data for hazard assessment estimation

Hypertension disorders are associated with higher rates of maternal, fetal, and infant mortality, and severe morbidity, especially in cases of severe preeclampsia, eclampsia, and HELLP syndrome. The aim of the study was to determine maternal outcomes in pregnant women with severe preeclampsia.The data source consisted of 349 cases with severe preeclampsia.A cross-sectional study was undertaken on 349 cases of severe preeclampsia in pregnancy.The patients selected for this study were from those who presented at Kermanshah University of Medical Sciences, Department of Obstetrics and Gynecology during 2007–2009.Statistical analysis was performed using SPSS 16 software and conducting Chi square and independent sample t tests. Demographic data involving age, parity, gestational age, clinical, and laboratory findings were recorded from the medical files. In addition, delivery route, indications of cesarean delivery, and maternal complications were determined.Of the 349 severely preeclampsia cases, among the 22 cases (6.3 %) who had suffered from eclamptic seizers, 17 cases (77.3 %) were in the age group of 18–35 years (P= 0.351) and 13 cases (59.1 %) in the gestational age group of 28–37 weeks (P= 0.112). One case (0.3 %) was demonstrated to have HELLP syndrome. Placental abruption was obstetric complication in 7.7 % (27 cases). Delivery route was vaginal in 120 cases (34.4 %), while 229 cases (65.6 %) underwent cesarean delivery. The most frequent maternal complication (37 cases) reported was coagulopathy (10.6 %).We concluded that severe preeclampsia and eclampsia are associated with higher rates of maternal severe morbidity and that these two factors still remain the major contributors to maternal morbidity in Iran.

Manual removal of placenta is performed in 1–3% of cases, and although it is a well-established and relatively safe procedure, it is not without complications. We carried out this study to determine whether intraumbilical vein oxytocin injection reduces the need for manual removal of placenta and shortens the third stage of labor, in comparison with placebo.

The rate of crustal deformation in Iran due to the Arabia–Eurasia collision is estimated. The results are based on new global positioning system (GPS) data. In order to address the problem of the distribution of the deformation in Iran, Iranian and French research organizations have carried out the first large-scale GPS survey of Iran. A GPS network of 28 sites (25 in Iran, two in Oman and one in Uzbekistan) has been installed and surveyed twice, in September 1999 and October 2001. Each site has been surveyed for a minimum observation of 4 days. GPS data processing has been done using the GAMIT-GLOBK software package. The solution displays horizontal repeatabilities of about 1.2 mm in 1999 and 2001. The resulting velocities allow us to constrain the kinematics of the Iranian tectonic blocks. These velocities are given in ITRF2000 and also relative to Eurasia. This last kinematic model demonstrates that (1) the north–south shortening from Arabia to Eurasia is 2–2.5 cm/year, less than previously estimated, and (2) the transition from subduction (Makran) to collision (Zagros) is very sharp and governs the different styles of deformation observed in Iran. In the eastern part of Iran, most of the shortening is accommodated in the Gulf of Oman, while in the western part the shortening is more distributed from south to north. The large faults surrounding the Lut block accommodate most of the subduction–collision transition.

We study the dynamics of targeted energy transfers in suppressing chatter instability in a single-degree-of-freedom (SDOF) machine tool system. The nonlinear regenerative (time-delayed) cutting force is a main source of machine tool vibrations (chatter). We introduce an ungrounded nonlinear energy sink (NES) coupled to the tool, by which energy transfers from the tool to the NES and efficient dissipation can be realized during chatter. Studying variations of a transition curve with respect to the NES parameters, we analytically show that the location of the Hopf bifurcation point is influenced only by the NES mass and damping coefficient. We demonstrate that application of a well-designed NES renders the subcritical limit cycle oscillations (LCOs) into supercritical ones, followed by Neimark–Sacker and saddle-node bifurcations, which help to increase the stability margin in machining. Numerical and asymptotic bifurcation analyses are performed and three suppression mechanisms are identified. The asymptotic stability analysis is performed to study the domains of attraction for these suppression mechanisms which exhibit good agreement with the bifurcations sets obtained from the numerical continuation methods. The results will help to design nonlinear energy sinks for passive control of regenerative instabilities in machining.