Spiniform phase-encoded metagratings entangling arbitrary rational-order orbital angular momentum

Quantum entanglements between integer-order and fractional-order orbital angular momentums (OAMs) have been previously discussed. However, the entangled nature of arbitrary rational-order OAM has long been considered a myth due to the absence of an effective strategy for generating arbitrary rational-order OAM beams. Therefore, we report a single metadevice comprising a bilaterally symmetric grating with an aperture, creating optical beams with dynamically controllable OAM values that are continuously varying over a rational range. Due to its encoded spiniform phase, this novel metagrating enables the production of an average OAM that can be increased without a theoretical limit by embracing distributed singularities, which differs significantly from the classic method of stacking phase singularities using fork gratings. This new method makes it possible to probe the unexplored niche of quantum entanglement between arbitrarily defined OAMs in light, which could lead to the complex manipulation of microparticles, high-dimensional quantum entanglement and optical communication. We show that quantum coincidence based on rational-order OAM-superposition states could give rise to low cross-talks between two different states that have no significant overlap in their spiral spectra. Additionally, future applications in quantum communication and optical micromanipulation may be found

Nontraumatic terminal ileal perforation

BACKGROUND: There is still confusion and controversy over the diagnosis and optimal surgical treatment of non traumatic terminal ileal perforation-a cause of obscure peritonitis. METHODS: This study was a prospective study aimed at evaluating the clinical profile, etiology and optimal surgical management of patients with nontraumatic terminal ileal perforation. RESULTS: There were 79 cases of nontraumatic terminal ileal perforation; the causes for perforation were enteric fever(62%), nonspecific inflammation(26%), obstruction(6%), tuberculosis(4%) and radiation enteritis (1%). Simple closure of the perforation (49%) and end to side ileotransverse anastomosis(42%) were the mainstay of the surgical management. CONCLUSION: Terminal ileal perforation should be suspected in all cases of peritonitis especially in developing countries and surgical treatment should be optimized taking various accounts like etiology, delay in surgery and operative findings into consideration to reduce the incidence of deadly complications like fecal fistula

Full-space Cloud of Random Points with a Scrambling Metasurface

With the rapid progress in computer science, including artificial intelligence, big data and cloud computing, full-space spot generation can be pivotal to many practical applications, such as facial recognition, motion detection, augmented reality, etc. These opportunities may be achieved by using diffractive optical elements (DOEs) or light detection and ranging (LIDAR). However, DOEs suffer from intrinsic limitations, such as demanding depth-controlled fabrication techniques, large thicknesses (more than the wavelength), Lambertian operation only in half space, etc. LIDAR nevertheless relies on complex and bulky scanning systems, which hinders the miniaturization of the spot generator. Here, inspired by a Lambertian scatterer, we report a Hermitian-conjugate metasurface scrambling the incident light to a cloud of random points in full space with compressed information density, functioning in both transmission and reflection spaces. Over 4044 random spots are experimentally observed in the entire space, covering angles at nearly 90 degrees. Our scrambling metasurface is made of amorphous silicon with a uniform subwavelength height, a nearly continuous phase coverage, a lightweight, flexible design, and low-heat dissipation. Thus, it may be mass produced by and integrated into existing semiconductor foundry designs. Our work opens important directions for emerging 3D recognition sensors, such as motion sensing, facial recognition, and other applications.113Nsciescopu

Health survey on anxiety, depression, and stress in Afghanistan: a large-scale cross-sectional study amid ongoing challenges

Background One of the most significant events in recent Afghan history is the rise of the Taliban and the war that followed, which had profound impacts on the lives of Afghans. The present study examined the mental health of Afghans living under the Taliban government. Methods Between June 5, 2023 and February 12, 2024, a cross-sectional study was conducted among the Afghan population in three key regions of Afghanistan. Data were collected using a pre-tested structured questionnaire. The 21-item Depression, Anxiety and Stress scale (DASS-21) was utilized to assess depression, anxiety and stress of the Afghan population. Ethical permission for this study was granted by the Afghanistan Center for Epidemiological Studies (ACES). Logistic regression models were employed to explore the relationship between socio-demographic characteristics and depression, anxiety, and stress among 2,698 participants. Results The prevalence of depression was 72.05%, anxiety was 71.94%, and stress was 66.49%. Multiple regression analysis indicated that gender (being female), economic status (being poor), residency (living in rural areas), education level (being illiterate), being a cigarette smoker, and having experienced a bad event during the past month were significantly associated with depression, anxiety and stress. Conclusion The findings of the present study show very high levels of anxiety, depression, and stress, most likely reflecting the profound impact of recent political, social, and economic changes. Notably, a significant majority of participants, particularly females and individuals above 35 years of age, reported severe to extremely severe mental health symptoms. The mental health crisis in Afghanistan is a complex and urgent issue that requires a comprehensive and compassionate response