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The Lancet. Global Health May 2024The Guiana Shield, a small region of South America, is currently one of the main hotspots of malaria transmission on the continent. This Amazonian area is characterised... (Review)
Review
The Guiana Shield, a small region of South America, is currently one of the main hotspots of malaria transmission on the continent. This Amazonian area is characterised by remarkable socioeconomic, cultural, health, and political heterogeneity and a high degree of regional and cross-border population mobility, which has contributed to the increase of malaria in the region in the past few years. In this context, regional cooperation to control malaria represents both a challenge and an indispensable initiative. This Viewpoint advocates for the creation of a regional cooperative mechanism for the elimination of malaria in the Guiana Shield. This strategy would help address operational and political obstacles to successful technical cooperation in the region and could contribute to reversing the regional upsurge in malaria incidence through creating a functional international control and elimination partnership.
Topics: Humans; Malaria; Protective Devices
PubMed: 38614635
DOI: 10.1016/S2214-109X(24)00047-0 -
Frontiers in Bioengineering and... 2023The amputee population according to the World-Health-Organization is about 40 million. However, there is a high abandon rate of socket prostheses for the lower limb... (Review)
Review
The amputee population according to the World-Health-Organization is about 40 million. However, there is a high abandon rate of socket prostheses for the lower limb (25%-57%). The direct connection between the external prosthesis and the patient's bone makes osseointegrated prostheses for transfemoral amputees advantageous (e.g., improvement of the motor control) compared to socket prostheses, which are currently the gold standard. However, similarly to other uncemented prostheses, the osseointegrated ones are at risk of aseptic loosening and adverse bone remodelling caused by stress-shielding. The preclinical assessment of these prostheses has already been evaluated using different methods which did not provide unanimous and comparable evidence. To compare data from different investigations, a clear and detailed overview of the methods used to assess the performance is necessary. In this review 17 studies investigating the primary stability, stress shielding and stress concentration of osseointegrated transfemoral prostheses are examined. Primary stability consists in the biomechanical stability upon implant insertion. Primary stability is assessed measuring extraction force (either with a pull-out or a push-out test) and micromotion at the interface between the implant and the host bone with LVDT ( test) or numerical models. Stress-shielding causes adaptive changes in the bone density around metal implants, and thus in the bone strength and stiffness. Stress-shielding is assessed with strain gauges or numerical models measuring the load transfer and the strain distribution on the surface of the femur, and between the implant and the bone respectively. Stress concentration can lead to the formation of cracks inside the bone, resulting in fractures. The stress concentration is assessed measuring the load transfer and the strain energy density at the interface between the implant and the bone, using numerical models. As a result, a global view and consensus about the methods are missing from all these tests. Indeed, different setup and loading scenario were used in the test, while different model parameters (e.g., bone properties) were used in the numerical models. Once the preclinical assessment method is established, it would be important to define thresholds and acceptance criteria for each of the possible failure scenarios investigated.
PubMed: 37662439
DOI: 10.3389/fbioe.2023.1237919 -
Cell Reports Jun 2023To kill bacteria, bacteriophages (phages) must first bind to a receptor, triggering the release of the phage DNA into the bacterial cell. Many bacteria secrete...
To kill bacteria, bacteriophages (phages) must first bind to a receptor, triggering the release of the phage DNA into the bacterial cell. Many bacteria secrete polysaccharides that had been thought to shield bacterial cells from phage attack. We use a comprehensive genetic screen to distinguish that the capsule is not a shield but is instead a primary receptor enabling phage predation. Screening of a transposon library to select phage-resistant Klebsiella shows that the first receptor-binding event docks to saccharide epitopes in the capsule. We discover a second step of receptor binding, dictated by specific epitopes in an outer membrane protein. This additional and necessary event precedes phage DNA release to establish a productive infection. That such discrete epitopes dictate two essential binding events for phages has profound implications for understanding the evolution of phage resistance and what dictates host range, two issues critically important to translating knowledge of phage biology into phage therapies.
Topics: Klebsiella pneumoniae; Bacteriophages; Porins; Polysaccharides
PubMed: 37224021
DOI: 10.1016/j.celrep.2023.112551 -
Materials (Basel, Switzerland) Oct 2023In shield tunneling projects, the selection of an accurate model to calculate the mechanical response of segment structure plays a crucial role in the design and cost of...
In shield tunneling projects, the selection of an accurate model to calculate the mechanical response of segment structure plays a crucial role in the design and cost of the project. The shell-spring and beam-spring models are two widely used methods for this purpose. However, it is still not clear how accurate and different these models are in calculation results under surcharge load. Therefore, to accurately calculate the internal forces and deformation of the segment structure and clarify the difference between the two models' results, the shell-spring and beam-spring models were established based on a subway shield tunnel project in Zhengzhou city. The reliability of the models was verified by comparing and analyzing the differences in deformation results between the models and field measurements. Furthermore, the safety of the segment structure was evaluated according to the ultimate bearing capacity of the normal section. The results declare that: (1) In the shell-spring model, the internal force gradually reduces from the edges towards the center of the segment width, and the shield segment exhibits a prominent non-plane strain state. (2) The internal force of the beam-spring model is larger than that of the shell-spring model. The axial force difference between the two models is relatively small; meanwhile, there is a larger disparity in the bending moment. However, with an increase in surcharge loading, the discrepancy in internal forces between the two models gradually decreases. (3) The calculation results of the shell-spring model are close to the field-measured values and the shield tunnel model test values, which verifies the accuracy and reliability of the shell-spring model. Therefore, it is more reasonable to use the shell-spring model to calculate the mechanical response of the segment structure. (4) With an increase in surcharge loading, the safety of the shield tunnel decreases gradually. Therefore, surcharge loading above the shield tunnel should be reasonably controlled to meet the requirements of the normal use of the shield segment. This manuscript aims to provide a reference for the future design and optimization of the shield tunnels' lining structure.
PubMed: 37895787
DOI: 10.3390/ma16206806 -
European Radiology Apr 2024The aim of the patient out-of-plane shield is to reduce the patient radiation dose. Its effect on tube current modulation was evaluated with the out-of-plane shield...
OBJECTIVES
The aim of the patient out-of-plane shield is to reduce the patient radiation dose. Its effect on tube current modulation was evaluated with the out-of-plane shield visible in the localizer but absent in the scan range in chest CT with different CT scanners.
METHODS
An anthropomorphic phantom was scanned with six different CT scanners from three different vendors. The chest was first scanned without any shielding, and then with the out-of-plane shield within the localizer but outside the imaged volume. All pitch values of each scanner were used. The tube current values with and without the out-of-plane shield were collected and used to evaluate the effect of overscanning and tube current modulation (TCM) on patient radiation dose.
RESULTS
The highest increase in cumulative mA was 217%, when the pitch was 1.531. The tube current value increased already 8.9 cm before the end of the scanned anatomy and the difference between the tube current of the last slices (with and without the out-of-plane shield in the localizer) was 976%.
CONCLUSION
Applying an out-of-plane shield outside the scanned volume but visible in the localizer images may increase the patient dose considerably if the scanner's TCM function is based only on localizer images.
CLINICAL RELEVANCE STATEMENT
The use of an out-of-plane shield in CT may strongly increase the tube current modulation and thus provide the patient with a higher radiation dose.
KEY POINTS
• Applying an out-of-plane shield outside the scanned volume but visible in the localizer images may increase patient radiation dose considerably. • The effect is visible with scanners that use solely localizer-based tube current modulation. • Features like overscanning may be difficult for the user to notice when planning the scanning, and yet they may affect tube current modulation and through it to patient dose.
Topics: Humans; Radiation Dosage; Tomography, X-Ray Computed; Tomography Scanners, X-Ray Computed; Thorax; Phantoms, Imaging
PubMed: 37707547
DOI: 10.1007/s00330-023-10211-3 -
Surgical Endoscopy Aug 2023Postoperative stricture and refractory stricture are severe adverse events which occur after expansive esophageal endoscopic submucosal dissection (ESD). The aim of this...
BACKGROUND
Postoperative stricture and refractory stricture are severe adverse events which occur after expansive esophageal endoscopic submucosal dissection (ESD). The aim of this study was to assess the efficacy of steroid injection, polyglycolic acid (PGA) shielding, and of additional steroid injection thereafter for the prevention of refractory esophageal stricture.
METHODS
This is a retrospective cohort study of 816 consecutive cases of esophageal ESD performed between 2002 and 2021 at the University of Tokyo Hospital. After 2013, all patients with a diagnosis of superficial esophageal carcinoma covering over 1/2 the esophageal circumference underwent preventive treatment immediately after ESD with either "PGA shielding", "steroid injection", or "steroid injection + PGA shielding". Additional steroid injection was performed for high-risk patients after 2019.
RESULTS
The risk of refractory stricture was especially high in the cervical esophagus (OR 24.77, p = 0.002) and after total circumferential resection (OR 894.04, p < 0.001). "Steroid injection + PGA shielding" was the only method significantly effective in preventing stricture occurrence (OR 0.36; 95% CI 0.15-0.83, p = 0.012). This method also decreased the risk of refractory stricture (OR 0.38; 95% CI 0.10-1.28, p = 0.096), but additional steroid injection was the only significantly effective method for prevention of refractory stricture (OR 0.42; 95% CI 0.14-0.98, p = 0.029).
CONCLUSION
Combining steroid injection and PGA shielding is effective for preventing post-ESD stricture and refractory stricture. Additional steroid injection is a viable option for patients at high-risk for refractory stricture.
Topics: Humans; Esophageal Stenosis; Constriction, Pathologic; Retrospective Studies; Esophageal Neoplasms; Steroids; Polyglycolic Acid; Endoscopic Mucosal Resection
PubMed: 37193890
DOI: 10.1007/s00464-023-10111-z -
Sisli Etfal Hastanesi Tip Bulteni 2023The transmission of severe acute respiratory syndrome coronavirus-2 occurs primarily through droplets, which highlights the importance of protecting the oral, nasal, and...
OBJECTIVES
The transmission of severe acute respiratory syndrome coronavirus-2 occurs primarily through droplets, which highlights the importance of protecting the oral, nasal, and conjunctival mucosas using personal protective equipment (PPE). The use of PPE can lead to communication difficulties between healthcare workers and patients. This study aimed to investigate changes in the acoustic parameters of speech sounds when different types of PPE are used.
METHODS
A cross-sectional study was conducted, enrolling 18 healthy male and female participants. They were instructed to produce a sustained [ɑː] vowel for at least 3 s to estimate voice quality. In addition, all Turkish vowels were produced for a minimum of 200 ms. Finally, three Turkish fricative consonants ([f], [s], and [ʃ]) were produced in a consonant/vowel/consonant format with different vowel contexts within a carrier sentence. Recordings were repeated under the following conditions: no PPE, surgical mask, N99 mask, face shield, surgical mask + face shield, and N99 mask + face shield. All recordings were subjected to analysis.
RESULTS
Frequency perturbation parameters did not show significant differences. However, in males, all vowels except [u] in the first formant (F1), except [ɔ] and [u] in the second formant (F2), except [ɛ] and [ɔ] in the third formant (F3), and only [i] in the fourth formant (F4) were significant. In females, all vowels except [i] in F1, except [u] in F2, all vowels in F3, and except [u] and [ɯ] in F4 were significant. Spectral moment values exhibited significance in both groups.
CONCLUSION
The use of different types of PPE resulted in variations in speech acoustic features. These findings may be attributed to the filtering effects of PPE on specific frequencies and the potential chamber effect in front of the face. Understanding the impact of PPE on speech acoustics contributes to addressing communication challenges in healthcare settings.
PubMed: 37900335
DOI: 10.14744/SEMB.2023.22556 -
International Journal of Molecular... Jul 2023Grape stems have emerged as a promising natural ingredient in the cosmetics industry due to their abundance of phenolic compounds, known for their antioxidant and... (Review)
Review
Grape stems have emerged as a promising natural ingredient in the cosmetics industry due to their abundance of phenolic compounds, known for their antioxidant and anti-inflammatory properties. These compounds have shown great potential in promoting skin health, fighting signs of aging, and shielding against environmental stressors. With high concentrations of resveratrol, flavonoids, and tannins, grape stems have garnered attention from cosmetic scientists. Research has indicated that phenolic compounds extracted from grape stems possess potent antioxidant abilities, effectively combating free radicals that accelerate aging. Moreover, these compounds have demonstrated the capacity to shield the skin from UV damage, boost collagen production, and enhance skin elasticity. Cosmetic formulations incorporating grape stem extracts have displayed promising results in addressing various skin concerns, including reducing wrinkles, fine lines, and age spots, leading to a more youthful appearance. Additionally, grape stem extracts have exhibited anti-inflammatory properties, soothing irritated skin and diminishing redness. Exploring the potential of grape stem phenolic compounds for cosmetics paves the way for sustainable and natural beauty products. By harnessing the beauty benefits of grape stems, the cosmetics industry can provide effective and eco-friendly solutions for consumers seeking natural alternatives. Ongoing research holds the promise of innovative grape stem-based formulations that could revolutionize the cosmetics market, fully unlocking the potential of these extraordinary botanical treasures.
Topics: Vitis; Antioxidants; Phenols; Plant Extracts; Cosmetics
PubMed: 37511513
DOI: 10.3390/ijms241411751 -
Pharmaceuticals (Basel, Switzerland) Aug 2023The intestinal barrier is a sum of the functions and structures consisting of the intestinal mucosal epithelium, mucus, intestinal flora, secretory immunoglobulins, and... (Review)
Review
The intestinal barrier is a sum of the functions and structures consisting of the intestinal mucosal epithelium, mucus, intestinal flora, secretory immunoglobulins, and digestive juices. It is the first-line defense mechanism that resists nonspecific infections with powerful functions that include physical, endocrine, and immune defenses. Health and physiological homeostasis are greatly dependent on the sturdiness of the intestinal barrier shield, whose dysfunction can contribute to the progression of numerous types of intestinal diseases. Disorders of internal homeostasis may also induce barrier impairment and form vicious cycles during the response to diseases. Therefore, the identification of the underlying mechanisms involved in intestinal barrier function and the development of effective drugs targeting its damage have become popular research topics. Evidence has shown that multiple signaling pathways and corresponding critical molecules are extensively involved in the regulation of the barrier pathophysiological state. Ectopic expression or activation of signaling pathways plays an essential role in the process of shield destruction. Although some drugs, such as molecular or signaling inhibitors, are currently used for the treatment of intestinal diseases, their efficacy cannot meet current medical requirements. In this review, we summarize the current achievements in research on the relationships between the intestinal barrier and signaling pathways. The limitations and future perspectives are also discussed to provide new horizons for targeted therapies for restoring intestinal barrier function that have translational potential.
PubMed: 37765024
DOI: 10.3390/ph16091216 -
Frontiers in Public Health 2023During the COVID-19 pandemic in the UK, those considered most vulnerable to adverse outcomes from infection were designated "clinically extremely vulnerable" and advised...
Mental health and life satisfaction among those advised to shield during the COVID-19 pandemic in the UK: a secondary analysis of the Understanding Society longitudinal study.
INTRODUCTION
During the COVID-19 pandemic in the UK, those considered most vulnerable to adverse outcomes from infection were designated "clinically extremely vulnerable" and advised to "shield." This involved prolonged confinement at home with strict limits on face-to-face contact, beyond national restrictions. Shielding ended in September 2021 and was considered likely to have harmed mental health and wellbeing. As the UK moved toward a new phase of "living with COVID-19" the mental health and wellbeing experiences of those advised to shield may have diverged from the general population.
METHODS
This study is a secondary analysis of nine "COVID-19 Survey" waves of Understanding Society, a longitudinal study of UK participants covering April 2020 to September 2021 alongside pre-pandemic baseline data. The prevalence of clinically significant psychological distress (General Health Questionnaire 12) and low life satisfaction were examined at each wave for participants with longitudinal responses across all waves, stratified by receipt of shielding guidance (Received = 410, Not received = 6,878). Mixed effects regression modeling examined associations between shielding guidance receipt and mental health and life satisfaction when adjusting for potential confounders including age and sex, pre-pandemic mental health/life satisfaction, and loneliness.
RESULTS
Those who received shielding guidance were more likely to experience poor mental health and low life satisfaction during the pandemic. However, this largely reflected differences in pre-pandemic baselines. Variation between waves broadly coincided with the changing burden of COVID-19 and associated restrictions, with similar patterns regardless of shielding guidance receipt. Regression modeling combining data across all waves indicated that receipt of shielding guidance did not independently predict adverse outcomes. However, poor pre-pandemic mental health and low life satisfaction, and frequent loneliness, as well as demographic factors including sex and age, consistently predicted adverse pandemic mental health and wellbeing.
DISCUSSION
While those who received shielding guidance did on average experience poorer mental health and life satisfaction during the pandemic, this study suggests this largely reflects existing inequalities. Drawing on data throughout the shielding program, it addresses an existing evidence gap. These findings reinforce the importance of addressing existing mental health inequalities in the recovery from the current pandemic and for future preparedness.
Topics: Humans; Mental Health; COVID-19; Pandemics; Longitudinal Studies; Personal Satisfaction; United Kingdom
PubMed: 37829093
DOI: 10.3389/fpubh.2023.1235903