The burden of headache disorders in the adult general population of the Kingdom of Saudi Arabia: estimates from a cross-sectional population-based study including a health-care needs assessment.

BACKGROUND: We have previously shown headache to be highly prevalent among adults in Saudi Arabia. Here we estimate associated symptom burden and impaired participation (impaired use of time, lost productivity and disengagement from social activity), and use these estimates to assess headache-related health-care needs in Saudi Arabia. METHODS: A randomised cross-sectional survey included 2,316 adults (18-65 years) from all 13 regions of the country. It used the standardised methodology of the Global Campaign against Headache with a culturally mandated modification: engagement by cellphone using random digit-dialling rather than door-to-door visits. Enquiry used the HARDSHIP questionnaire, with diagnostic questions based on ICHD-3 beta, questions on symptom burden, enquiries into impaired participation using the HALT index and questions about activity yesterday in those reporting headache yesterday (HY). Health-care "need" was defined in terms of likelihood of benefit. We counted all those with headache on ≥ 15 days/month, with migraine on ≥ 3 days/month, or with migraine or TTH and meeting either of two criteria: a) proportion of time in ictal state (pTIS) > 3.3% and intensity ≥ 2 (moderate-severe); b) ≥ 3 lost days from paid work and/or household chores during 3 months. RESULTS: For all headache, mean frequency was 4.3 days/month, mean duration 8.4 h, mean intensity 2.3 (moderate). Mean pTIS was 3.6%. Mean lost days from work were 3.9, from household chores 6.6, from social/leisure activities 2.0. Of participants reporting HY, 37.3% could do less than half their expected activity, 19.8% could do nothing. At population-level (i.e., for every adult), 2.5 workdays (potentially translating into lost GDP), 3.6 household days and 1.3 social/leisure days were lost to headache. According to HY data, mean total impaired participation (not distinguishing between work, household and social/leisure) was 6.8%. A total of 830 individuals (35.8%) fulfilled one or more of our needs assessment criteria. CONCLUSION: A very high symptom burden is associated with a commensurately high burden of impaired participation. The economic cost appears to be enormous. Over a third of the adult population are revealed to require headache-related health care on the basis of being likely to benefit, demanding highly efficient organization of care.

Viral infection and spread are inhibited by the polyubiquitination and downregulation of TRPV2 channel by the interferon-stimulated gene TRIM21.

Interferon (IFN) contributes to the host's antiviral response by inducing IFN-stimulated genes (ISGs). However, their functional targets and the mechanism of action remain elusive. Here, we report that one such ISG, TRIM21, interacts with and degrades the TRPV2 channel in myeloid cells, reducing its expression and providing host protection against viral infections. Moreover, viral infection upregulates TRIM21 in paracrine and autocrine manners, downregulating TRPV2 in neighboring cells to prevent viral spread to uninfected cells. Consistently, the Trim21-/- mice are more susceptible to HSV-1 and VSV infection than the Trim21+/+ littermates, in which viral susceptibility is rescued by inhibition or deletion of TRPV2. Mechanistically, TRIM21 catalyzes the K48-linked ubiquitination of TRPV2 at Lys295. TRPV2K295R is resistant to viral-infection-induced TRIM21-dependent ubiquitination and degradation, promoting viral infection more profoundly than wild-type TRPV2 when reconstituted into Lyz2-Cre;Trpv2fl/fl myeloid cells. These findings characterize targeting the TRIM21-TRPV2 axis as a conducive strategy to control viral spread to bystander cells.

Long-term clinical outcomes of arthroscopic supraspinatus tendon repair using the single anchor tension band technique - Minimum 5-years follow-up.

Background: The primary aim of this study was to assess the long-term patient reported outcomes of arthroscopic rotator cuff tear (ARCR) using a single anchor tension band (TB) technique for small and medium supraspinatus tears at minimum 5-years follow-up. Methods: A retrospective cohort study of consecutive ARCRs of small and medium supraspinatus tears using a knotless single anchor TB technique with minimum 5-year follow-up was carried out. Outcomes of interest included: range of motion (ROM) on examination under anaesthesia (EUA), visual analogue scale (VAS), American Shoulder and Elbow Surgeons (ASES) scores, Oxford Shoulder Score (OSS) and Short-Form (SF-12). Results: From 243 consecutive ARCR procedures, 82 patients with a mean age of 55 ± 9.5 years met the inclusion criteria at 6.7 ± 1.5 years follow-up. There were significant improvements in VAS (5.5 ± 2.2 vs. 0.7 ± 1.5), ASES (47.6 ± 16.8 vs. 92.8 ± 13.0), OSS (31.3 ± 7.2 vs. 45.3 ± 3.5) and SF-12 (37.6 ± 7.6 vs. 50.3 ± 7.7) post-operatively (all p < 0.001). Conclusions: The single anchor TB ARCR technique has excellent patient reported outcomes at a minimum of 5 years and is suitable for supraspinatus tears smaller than 20 mm in the sagittal plane. Level of evidence: Level IV; Consecutive Case Series.

Developing and validating an implantable suture tension sensor.

Introduction: Suture tension has a direct influence on the sutured tissue. For abdominal wall closure, suture tension should be optimal without causing tissue necrosis, which can result in surgical site infection or incisional hernia. The purpose of the present study is to evaluate a device that can measure suture tension in-situ and in real-time. Materials and methods: A cheap, commercially available analog-to-digital converter was used, in conjunction with a force sensing resistor. A sensor probe housing was designed and 3D-printed. In order to test the sensor, a mechanical, computer controlled human abdominal wall model called the AbdoMAN was used. Results: An implantable suture tension sensor was developed, keeping cost-effectiveness in mind. This sensor can translate tension in the suture into a downward force, applied to the force sensing resistor. The sensor's raw readout was characterized using a set of weights, from which a formula correlating the readout to a specific force, was derived. Preliminary validation was successfully performed using the AbdoMANmodel, which showed a progressive rise in suture tension when the intra-abdominal pressure was artificially increased over time. Conclusion: The implantable suture tension sensor appeared to be capable of recording real time changes in suture tension, and the. validation process of this sensor has been initiated. With the information from devices like this, a much better understanding of the issues at play in the development of incisional hernia can be gained.

A Case of Tension Pneumomediastinum Treated With Mediastinal Drainage Using a Semi-flexible Fiberscope via a Subxiphoid Approach.

Tension pneumomediastinum with hemodynamic failure is a rare but life-threatening condition. Rapid decompression of the mediastinum by drainage is essential to save the patient's life. This report presents a case of tension pneumomediastinum that developed during conservative management of a pneumomediastinum associated with idiopathic pulmonary fibrosis. Endoscopically guided mediastinal drainage was successfully performed in the emergency situation of tension pneumomediastinum. Using the semi-flexible fiberscope inserted through a subxiphoid approach, the drainage catheter was easily and safely placed at the appropriate site in the mediastinum. Good mediastinal decompression was achieved, and the patient was out of this critical condition.

Assessment of the Suitability of Selected Linear Actuators for the Implementation of the Load-Adaptive Biological Principle of Redundant Motion Generation.

The load-adaptive behavior of the muscles in the human musculoskeletal system offers great potential for minimizing resource and energy requirements in many technical systems, especially in drive technology and robotics. However, the lack of knowledge about suitable technical linear actuators that can reproduce the load-adaptive behavior of biological muscles in technology is a major reason for the lack of successful implementation of this biological principle. In this paper, therefore, the different types of linear actuators are investigated. The focus is particularly on artificial muscles and rope pulls. The study is based on literature, on the one hand, and on two physical demonstrators in the form of articulated robots, on the other hand. The studies show that ropes are currently the best way to imitate the load-adaptive behavior of the biological model in technology. This is especially illustrated in the context of this paper by the discussion of different advantages and disadvantages of the technical linear actuators, where ropes, among other things, have a good mechanical and control behavior, which is very advantageous for use in an adaptive system. Finally, the next steps for future research are outlined to conclude how ropes can be used as linear actuators to transfer load-adaptive lightweight design into technical applications.

[Effectiveness of transverse double "8"-shaped tension band technique for Lawrence zone â fracture of the fifth metatarsal base].

Objective: To explore the effectiveness of transverse double "8"-shaped tension band technique in the treatment of Lawrence zoneⅠfracture of the 5th metatarsal base. Methods: Between February 2019 and October 2021, 15 patients with Lawrence zoneⅠfracture of the 5th metatarsal base were treated with transverse double "8"-shaped tension band technique. There were 8 males and 7 females, with a median age of 40 years (range, 23-59 years). The fractures were caused by sprains. The time from injury to operation was 3-7 days (mean, 4.1 days). X-ray films were taken to observe the fracture healing and the anchor looseness and detachment. The foot function was evaluated by American Orthopaedic Foot and Ankle Society (AOFAS) score, visual analogue scale (VAS) score, and the eversion angle of the calcaneal talus joint. Results: The incisions healed by first intention after operation in 14 cases and the incision healed poorly in 1 case. All patients were followed up 8-12 months (median, 10 months). The imaging examination showed that all fractures healed well, with a healing time of 10-14 weeks (mean, 11.7 weeks). At last follow-up, AOFAS score was 82-100 (median, 98); 13 cases were excellent and 2 cases were good, with an excellent and good rate of 100%. VAS score was 0-3 (median, 1). Three cases had mild limited ankle joint range of motion, while 12 cases had normal range of motion. The eversion angle of the calcaneal talus joint was 25°-32° (median, 30°). Conclusion: The application of transverse double "8"-shaped tension band technique for Lawrence zone Ⅰ fracture of the 5th metatarsal base has advantages such as simple operation, avoidance of secondary operation, and reduction of foreign body sensation, with definite effectiveness.

Limited oxygen in standard cell culture alters metabolism and function of differentiated cells.

The in vitro oxygen microenvironment profoundly affects the capacity of cell cultures to model physiological and pathophysiological states. Cell culture is often considered to be hyperoxic, but pericellular oxygen levels, which are affected by oxygen diffusivity and consumption, are rarely reported. Here, we provide evidence that several cell types in culture actually experience local hypoxia, with important implications for cell metabolism and function. We focused initially on adipocytes, as adipose tissue hypoxia is frequently observed in obesity and precedes diminished adipocyte function. Under standard conditions, cultured adipocytes are highly glycolytic and exhibit a transcriptional profile indicative of physiological hypoxia. Increasing pericellular oxygen diverted glucose flux toward mitochondria, lowered HIF1α activity, and resulted in widespread transcriptional rewiring. Functionally, adipocytes increased adipokine secretion and sensitivity to insulin and lipolytic stimuli, recapitulating a healthier adipocyte model. The functional benefits of increasing pericellular oxygen were also observed in macrophages, hPSC-derived hepatocytes and cardiac organoids. Our findings demonstrate that oxygen is limiting in many terminally-differentiated cell types, and that considering pericellular oxygen improves the quality, reproducibility and translatability of culture models.

Biomechanical Increase in Cervical Esophageal Wall Tension during Peristalsis.

During pharyngeal phase of swallowing circumferential tension of the cervical esophagus (CTE) increases caused by a biomechanical process of laryngeal elevation pulling the cervical esophagus orad. The esophagus contracts longitudinally during esophageal peristalsis, therefore, we hypothesized that CTE increases during esophageal peristalsis by a biomechanical process. METHODS: We investigated this hypothesis using 28 decerebrate cats instrumented with EMG electrodes on the pharynx and esophagus, and esophageal manometry. We recorded CTE, distal esophageal longitudinal tension (DET), and orad laryngeal tension (OLT) using strain gauges. Peristalsis was stimulated by injecting saline into esophagus or nasopharynx. We investigated the effects of transecting the pharyngo-esophageal nerve (PEN), hypoglossal nerve (HG), or administering (10 mg/kg, IV) hexamethonium (HEX). RESULTS: We found that the durations of CTE and DET increased and OLT decreased simultaneously during the total extent of esophageal peristalsis. CTE duration was highly correlated with DET, but not esophageal EMG or manometry. The peak magnitudes of the DET and CTE were highly correlated. After HEX administration, peristalsis in the distal esophagus did not occur, and the duration of the CTE response decreased. PEN transection blocked the occurrence of cricopharyngeal or cervical esophageal response during peristalsis, but had no significant effect on the CTE response. HG transection had no significant effect on CTE. CONCLUSION: We conclude that there is a significant CTE increase, independent of laryngeal elevation or esophageal muscle contraction, which occurs during esophageal peristalsis. This response is a biomechanical process caused by esophageal shortening that occurs during esophageal longitudinal contraction of esophageal peristalsis.

Ether lipids influence cancer cell fate by modulating iron uptake.

Cancer cell fate has been widely ascribed to mutational changes within protein-coding genes associated with tumor suppressors and oncogenes. In contrast, the mechanisms through which the biophysical properties of membrane lipids influence cancer cell survival, dedifferentiation and metastasis have received little scrutiny. Here, we report that cancer cells endowed with a high metastatic ability and cancer stem cell-like traits employ ether lipids to maintain low membrane tension and high membrane fluidity. Using genetic approaches and lipid reconstitution assays, we show that these ether lipid-regulated biophysical properties permit non-clathrin-mediated iron endocytosis via CD44, leading directly to significant increases in intracellular redox-active iron and enhanced ferroptosis susceptibility. Using a combination of in vitro three-dimensional microvascular network systems and in vivo animal models, we show that loss of ether lipids also strongly attenuates extravasation, metastatic burden and cancer stemness. These findings illuminate a mechanism whereby ether lipids in carcinoma cells serve as key regulators of malignant progression while conferring a unique vulnerability that can be exploited for therapeutic intervention.

Analysis of postoperative complications 5 years after osteosynthesis of patella fractures-a retrospective, multicenter cohort study.

PURPOSE: The study aims to investigate the influence of patient- and fracture-specific factors on the occurrence of complications after osteosynthesis of patella fractures and to compare knee joint function, activity, and subjective pain levels after a regular postoperative course and after complications in the medium term. METHODS: This retrospective, multicenter cohort study examined patients who received surgery for patella fracture at level 1 trauma centers between 2013 and 2018. Patient demographics and fracture-specific variables were evaluated. Final follow-up assessments included patient-reported pain scores (NRS), subjective activity and knee function scores (Tegner Activity Scale, Lysholm score, IKDC score), complications, and revisions. RESULTS: A total of 243 patients with a mean follow-up of 63.4 ± 21.3 months were included. Among them, 66.9% of patients underwent tension band wiring (TBW), 19.0% received locking plate osteosynthesis (LPO), and 14.1% underwent screw osteosynthesis (SO). A total of 38 patients (15.6%) experienced complications (TBW: 16.7%; LPO: 15.2%; SO: 11.8%). Implant-related complications of atraumatic fragment dislocation and material insufficiency/dislocation, accounted for 50% of all complications, were significantly more common after TBW than LPO (p = 0.015). No patient-specific factor was identified as a general cause for increased complications. Overall, particularly following complications such as limited range of motion or traumatic refracture, functional knee scores were significantly lower and pain levels were significantly higher at the final follow-up when a complication occurred. Implant-related complications, however, achieved functional scores comparable to a regular postoperative course without complications after revision surgery. CONCLUSION: The present study demonstrated that implant-related complications occurred significantly more often after TBW compared to LPO. The complication rates were similar in all groups.

The burden attributable to primary headache disorders in children and adolescents in Ethiopia: estimates from a national schools-based study.

BACKGROUND: We previously reported high prevalences of headache disorders among children (6-11 years) and adolescents (12-17 years) in Ethiopia. Here we provide data on headache-attributed burden collected contemporaneously from the same study participants. Part of the global schools-based programme within the Global Campaign against Headache, the study is the first to present such data from sub-Saharan Africa. METHODS: A cross-sectional survey following the generic protocol for the global study was conducted in six schools (urban and rural), in Addis Ababa city and three regions of Ethiopia. The child or adolescent versions of the Headache-Attributed Restriction, Disability, Social Handicap and Impaired Participation (HARDSHIP) structured questionnaires were self-completed under supervision by pupils in class. Headache diagnostic questions were based on ICHD-3 beta but for the inclusion of undifferentiated headache (UdH). RESULTS: Of 2,349 eligible participants, 2,344 completed the questionnaires (1,011 children [43.1%], 1,333 adolescents [56.9%]; 1,157 males [49.4%], 1,187 females [50.6%]; participating proportion 99.8%). Gender- and age-adjusted 1-year prevalence of headache, reported previously, was 72.8% (migraine: 38.6%; tension-type headache [TTH]: 19.9%; UdH: 12.3%; headache on ≥ 15 days/month (H15+): 1.2%). Mean headache frequency was 2.6 days/4 weeks but, with mean duration of 2.7 h, mean proportion of time with headache was only 1.0% (migraine: 1.4%; TTH: 0.7%; H15+: 9.1%). Mean intensity was 1.8 on a scale of 1-3. Symptomatic medication was consumed on about one third of headache days across headache types. Lost school time reportedly averaged 0.7 days over the preceding 4 weeks, representing 3.5% of school time, but was 2.4 days/4 weeks (12.0%) in the important small minority with H15+. However, actual absences with headache the day before indicated averages overall of 9.7% of school time lost, and 13.3% among those with migraine. Emotional impact and quality-of-life scores reflected other measures of burden, with clear adverse impact gradients (H15 + > migraine > TTH > UdH). CONCLUSIONS: The high prevalence of headache among children and adolescents in Ethiopia, who represent half its population, is associated with substantial burden. Lost school time is probably the most important consequence. Estimates suggest a quite deleterious effect, likely to be reflected in both individual prospects and the prosperity of society.

Tension Pneumomediastinum in Anti-MDA5 Antibody-positive Dermatomyositis-associated Interstitial Lung Disease: A Case Report and Literature Review.

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis (DM)-associated interstitial lung disease (ILD) can sometimes be complicated by pneumomediastinum, although tension pneumomediastinum is extremely rare. We herein report a case of anti-MDA5 antibody-positive DM-ILD that worsened subcutaneous and mediastinal emphysema during treatment. Hypotension and worsening respiratory failure were observed on day 20 of treatment. Mediastinal drainage under video-assisted thoracoscopic surgery promptly improved the patient's circulatory and respiratory status. Tension pneumomediastinum is a rare complication; however, it is a serious condition that may lead to hypotension or cardiac arrest and requires a prompt diagnosis and treatment.

The prevalence of headache in the adult population of Morocco: a cross-sectional population-based study.

BACKGROUND: The series of population-based studies conducted by the Global Campaign against Headache has, so far, included Pakistan and Saudi Arabia from the Eastern Mediterranean Region. The Maghreb countries of North Africa, also part of this Region, are geographically apart and culturally very different from these countries. Here we report a study in Morocco. METHODS: We applied the standardised methodology of Global Campaign studies, with cluster-randomized sampling in regions of Morocco selected to be representative of its diversities. In three of these regions, in accordance with this methodology, we made unannounced visits to randomly selected households and, from each, interviewed one randomly selected adult member (aged 18-65 years) using the HARDSHIP structured questionnaire translated into Moroccan Arabic and French. In a fourth region (Fès), because permission for such sampling was not given by the administrative authority, people were randomly stopped in streets and markets and, when willing, interviewed using the same questionnaire. This was a major protocol violation. RESULTS: We included 3,474 participants, 1,074 (41.7%) from Agadir, 1,079 (41.9%) from Marrakech, 422 (16.4%) from Tétouan and 899 from Fès. In a second protocol violation, interviewers failed to record the non-participating proportion. In the main analysis, excluding Fès, observed 1-year prevalence of any headache was 80.1% among females, 68.2% among males. Observed 1-day prevalence (headache yesterday) was 17.8%. After adjustment for age and gender, migraine prevalence was 30.8% (higher among females [aOR = 1.6]) and TTH prevalence 32.1% (lower among females [aOR = 0.8]). Headache on ≥ 15 days/month (H15+) was very common (10.5%), and in more than half of cases (5.9%) associated with acute medication overuse (on ≥ 15 days/month) and accordingly diagnosed as probable medication-overuse headache (pMOH). Both pMOH (aOR = 2.6) and other H15+ (aOR = 1.9) were more common among females. In the Fès sample, adjusted prevalences were similar, numerically but not significantly higher except for other H15+. CONCLUSIONS: While the 1-year prevalence of headache among adults in Morocco is similar to that of many other countries, migraine on the evidence here is at the upper end of the global range, but not outside it. H15 + and pMOH are very prevalent, contributing to the high one-day prevalence of headache.

The prevalence and demographic associations of headache in the adult population of Peru: a national cross-sectional population-based study.

BACKGROUND: The Global Campaign against Headache is conducting a series of population-based studies to fill the large geographical gaps in knowledge of headache prevalence and attributable burden. One major region not until now included is South America. Here we present a study from Peru, a country of 32.4 million inhabitants located at the west coast of South America, notable for its high Andes mountains. METHODS: The study was conducted in accordance with the standardized methodology used by the Global Campaign. It was a cross-sectional survey using cluster randomised sampling in five regions to derive a nationally representative sample, visiting households unannounced, and interviewing one randomly selected adult member (aged 18-65 years) of each using the Headache-Attributed Restriction, Disability, Social Handicap and Impaired Participation (HARDSHIP) questionnaire translated into South American Spanish. The neutral screening question ("Have you had headache in the last year?") was followed by diagnostic questions based on ICHD-3 and demographic enquiry. RESULTS: The study included 2,149 participants from 2,385 eligible households (participating proportion 90.1%): 1,065 males and 1,084 females, mean age 42.0 ± 13.7 years. The observed 1-year prevalence of all headache was 64.6% [95% CI: 62.5-66.6], with age-, gender- and habitation-adjusted prevalences of 22.8% [21.0-24.6] for migraine (definite + probable), 38.9% [36.8-41.0] for tension-type headache (TTH: also definite + probable), 1.2% [0.8-1.8] for probable medication-overuse headache (pMOH) and 2.7% [2.1-3.5] for other headache on ≥ 15 days/month (H15+). One-day prevalence of headache (reported headache yesterday) was 12.1%. Migraine was almost twice as prevalent among females (28.2%) as males (16.4%; aOR = 2.1; p < 0.001), and strongly associated with living at very high altitude (aOR = 2.5 for > 3,500 versus < 350 m). CONCLUSION: The Global Campaign's first population-based study in South America found headache disorders to be common in Peru, with prevalence estimates for both migraine and TTH substantially exceeding global estimates. H15 + was also common, but with fewer than one third of cases diagnosed as pMOH. The association between migraine and altitude was confirmed, and found to be strengthened at very high altitude. This association demands further study.

Zebras in Adult Dysphagia Workup: Where to Look When You Think You Have Looked Everywhere.

While many patients who present with dysphagia have a clinically identifiable cause of dysphagia, the etiology of swallowing difficulty is oftentimes a diagnostic enigma. The aim of this article is to review possible etiologies of dysphagia when objective evidence of dysphagia is lacking. Included in this discussion are cricopharyngeal spasm, retrograde cricopharyngeal dysfunction, muscle tension dysphagia, dysphagia secondary to medications, and functional dysphagia.

Probing Effect of 6 MeV Electron Beam Irradiation on Haemoglobin Protein Using Spectroscopic Techniques.

In this work, we study the effect of 6 MeV electron beam irradiation on the physicochemical properties of lyophilized Human Haemoglobin A (HbA). Electron beams generated from Race Track Microtron accelerator with energy 6 MeV were used to irradiate HbA at fluences of 5 × 1014 e-/cm2 and 10 × 1014 e-/cm2. Pristine and electron beam irradiated HbA were characterized using UV-visible and Fourier transform infrared spectroscopy (FTIR) spectroscopy. The interfacial tension of the aqueous solutions of HbA are also analysed by pendant drop method. Absorbance intensity, % transmittance and interfacial tension decrease with fluence. The peak position of the Soret band (λsoret = 404 nm) remains unaffected by the fluences. FTIR spectroscopy confirms the changes in the secondary structure of the haemoglobin. In the amide band I, the percentage of α-helix reduced from 8% to 1%, and an increase in ß-sheet (19% to 29%) and ß helix (6.3% to 15%) is observed. Interfacial tension decreases from 46.0 mN/m and 44.0 mN/m with increase in irradiation dose. These finding provides realistic guideline for biological cells exposure to electron beam radiation doses.

Experimental study on large-scale compression members strengthened with circumferential prestressed CFRP plate.

There have been many research reports on the reinforcement of small-sized square columns with a cross-section of 200mm-300mm using prestressed carbon fiber-reinforced polymer (CFRP) materials, while there are few studies on piers in bridge and tower columns in cable-stayed bridges with a cross-section of several meters or even tens of meters. The horizontal prestressed steel tendons in the anchorage zone of tower columns in cable-stayed bridge replaced by prestressed CFRP sheets can not only facilitate construction and maintenance, but also have good fatigue resistance. The prestressed CFRP plate is used to reinforce the large-sized tower columns by using a specific device to tension the CFRP plate wrapped around the surface of the members. The tensioning device and test pedestal based on WSGG (wave-shaped-gear-grip) anchor clamping of CFRP plate have been developed in this paper, and the CFRP plate circumferential tensioning tests on the pedestal have been conducted. The test results are as follows: (1) the developed device can achieve circumferential tensioning of single-layer CFRP plate to 0.5ftk of the material, reaching a tensile force of 60kN, and generate effective restraint pressure on a 2-m long composite compression component; (2)The calculation formula for the constraint pressure generated by the circumferential prestressed CFRP sheet on the component has been derived and verified, and the maximum error between the calculated value and the experimental value is within 5%; (3) When iron sheet serves as the interface medium between CFRP plate and compression components, the prestress loss of the CFRP plate tensioned at one end is about 84% and 58%-60% when tensioned at both ends. It can be seen that the effective prestress of the CFRP plate with iron sheet as the interface medium is relatively small. Meanwhile, based on the distribution of compressive stress in the components and the effective pre tension value of CFRP plate, it can be seen that two end tensioning is better than one end tensioning; (4) The tensile stress of CFRP plate along the member is a cubic function when the tension force is 60kN, so it is deduced that the constrained compressive stress generated by CFRP plate on the member is a quadratic function distribution.

Characterization of human skin under tension using terahertz time domain spectroscopy.

This paper introduces a spectral analysis method for monitoring the human skin in vivo based on a combination of terahertz time-domain spectroscopy (THz-TDS) and optical coherence tomography (OCT). The method can quantitatively measure the refractive index, thickness and transmission coefficient of epidermis, and the refractive index of dermis in natural, as well as the tension condition of the skin. An optically reflective model for the multilayer structure of the skin is first established. The initial thickness of the epidermis is then measured by OCT as a known quantity for the established model. By fitting the established model to the experimentally obtained THz-TDS signals, the above parameters of the skin can be calibrated. Furthermore, the dependence of these skin parameters on the tension status are investigated. This study provides a means for terahertz technology to measure the skin in vivo.

Let us move forward: Comment on "are generations a useful concept?"

Generational labels (e.g., Millennials and Baby Boomers) are widely used in daily life to represent the unique characteristics of groups of people. However, the existence of generational differences remains contentious. In their focal paper, Costanza et al. (2023) critically reviewed the literature on generational differences and proposed two future research directions: the social constructionist and lifespan development perspectives. In this commentary, we aimed to extend the proposed directions for future research on generational differences by integrating the two perspectives into one theoretical framework. Future research should investigate how proximal social relationships (e.g., intergenerational relations) and distal social norms (e.g., age norms) change over historical time and whether these historical changes shape individuals' development and aging. The theoretical framework that integrates the two proposed research directions may stimulate research on generational differences to progress beyond the concept of generations.