bluuebunny/crossref_metadata_2025 huggingface dataset:
Adverse Childhood Experiences and worsened social relationships in adult life among Polish medical and dental students
Authors: Drożak Paulina , Duda Piotr , Augustowska Katarzyna , Drożak Martyna , Bryliński Łukasz , Bura Agata , Rudnicka-Drożak Ewa
Published: September 2021

Introduction and purpose. Adverse Childhood Experiences (ACEs) are potentially traumatic events experienced before the age of 18 that have lasting negative effects on physical and mental health. Numerous studies have shown that exposure to Adverse Childhood Experiences increases the probability of chronic health conditions, such as obesity, diabetes, coronary heart disease, asthma, depression or PTSD. The aim of the study was to investigate the prevalence of Adverse Childhood Experiences among medical and dental students of Polish Medical Universities and to examine an association between ACEs and chosen factors associated with social relationships of the students.Material and method. A total of 1162 medical and dental students from each year of education and 18 different Polish universities took part in the study. The research tool contained the Adverse Childhood Experiences standardized questionnaire and authors’ questions.Results. More than a half of the students (57.4%) had at least 1 exposure to ACEs. 8.43% of them experienced 4 or more childhood adversities. The most commonly reported ACEs were: emotional neglect (23.06%), emotional abuse (22.98%) and mental illness or a suicide attempt in a household member (21.86%). An overall graded relationship was found between ACE score and: parents’ lower level of education, negative relationship with parents, siblings and friends and having a diagnosis of depression.Conclusions. Adverse Childhood Experiences are common among Polish medical and dental students and are associated with worsened social relationships and depression in adult life of the students. It is important to implement strategies that aim to prevent ACEs and help to build social support networks for those that are affected by them.
Assessment of static and dynamic balance in patients after total hip arthroplasty based on the Tinetti Test
Authors: Maziuk Norbert , Szczypiór-Piasecka Karina , Mińko Alicja
Published: September 2021

Introduction: A degenerative disease of a hip joint (osteoarthritis) is a chronic affliction which causes progressive degeneration of a hip joint and tissue located around it. It inflicts limitation of locomotor skills, deteriorates life quality to a significant extent, and prevents a patient from normal activities in daily life. In Poland, more than 3 million people suffer from osteoarthritis. The disease symptoms are pain, limitation of mobility scope in a joint, postural and gait disorders, and positioning of a lower limb in non-functional position. The aim of the study was to analyze the gait pattern and to assess the static and dynamic balance of people qualified for hip joint arthroplasty, as well as possibility of falling.Material and methods: The Tinetti Test has been used for the research in question. This test has been completed in patients awaiting for hip joint arthroplasty, and once more on a third day upon completion of arthroplasty, in the Department and Clinic of Orthopaedics, Traumatology and Oncology of Locomotor System of the Pomeranian Medical University in Szczecin. This test has included a group of 31 – 11 women and 20 men.Results: The mean age of the research group was 65.1 years. The intensity of pain in the hip joint, based on the VAS scale before and after the procedure, was 6.53 and 5.22 points, respectively. The average number of points obtained by the patient in the Tinetti Test before the surgery was 22.71 points. On the third day of hip surgery, the mean number of points decreased to 18.81 points.Conclusions: Patients treated with alloplastic surgery of a hip joint show lower static and dynamic balance. Upon completion of the surgery, the patients are more prone to fall. The patients with completed hip joint arthroplasty show symptoms of locomotor system disorders.
Stress resistance and adaptive capacities of cardiovascular system of graduating teenagers with different level of studying load
Authors: Khomenko Olena , Nekhanevych Oleh , Simonova Sofiia , Kovalenko Yevgeniia , Kosse Valentin , Topka Elvira
Published: September 2021

The analysis of stress resistance and adaptive reactions of cardiovascular system was conducted according to the level of heart rate variability of graduating teenagers regardless of their studying load. The survey was held in Dnipro (Ukraine) based on a method of anonymous questioning using a personally developed and standardized questionnaire. 84 teenagers that are students of the 11th form of comprehensive schools and lyceums were asked. 22 children of relevant age from different countries made up a comparison group, among them an online survey was conducted by means of similar English-language questionnaire in Google-form. The assessment of heart rate variability of 46 graduates was given, using a cloud technology of automated interpretation of ECG (PRECISE). Statistical processing was conducted using the application program Statistica 6.0 for Windows. Decreasing of stress resistance and significant violations of adaptive cardiovascular reactions in teenagers of graduating classes in Dnipro was set, especially in lyceum students as a result of insufficient rest of students. During the educational period significant violation of adaptive capabilities takes place in 65.6 % of lyceum students: exhausting of functional organism’s reserves with decline in RMSSD to (17.2±1.9) meters per second, Total power to (607.25±11.9) meters per second has been observed in half of the students. At the same time, 85.3 % of the comprehensive school students have sufficient adaptive and worse resource capacities of an organism. For the first time it was highlighted that the autonomous nervous system among the examined teenagers operates in the imbalance regime of its sympathetic and parasympathetic link with a prevalence of sympathicotonia among the 50 % of lyceum students during a recessional period, 56.3 % during an educational period, while vagotonia and eutonia prevail among the comprehensive school students, not depending on the school year period. It was found out that physical activity promoted increased body resistance to stress factors. The efficient determination of heart rhythm variability (PRECISE diagnostics) was proven to control the functional state and adaptive capabilities of graduates’ cardiovascular system.
Association Between Male fertility and Vitamin D
Authors: Piekarska Ewa , Pawlicki Mateusz , Łopuszyńska Anna , Kozioł Magdalena , Krasa Aleksandra , Piecewicz-Szczęsna Halina
Published: September 2021

Introduction: Infertility affects millions of people of reproductive age worldwide. Male infertility may be caused by a number of different factors including problems in the ejection of semen, absence or low levels of sperm, or abnormal morphology and movement of the sperm. Environmental and lifestyle factors also have a meaningful impact on male reproductive system. Fertility care should include the prevention, diagnosis and treatment of the disorder. That is why numerous studies have explored the role of vitamin D in regulating the functioning of the reproductive system.Aim of study: Investigation of correlation between Vitamin D and male fertility.Results: Studies consistently show that Vitamin D deficiency has a negative influence on male fertility. Number of trials show that the mean value of Vitamin D serum levels tend to be significantly lower in infertile men compared to fertile men. Vitamin D insufficiency and deficiency has been noticed to be associated with poor semen quality (lower sperm concentrations, lower motility). It became  evident that vitamin D exhibits positive correlation with the male fertility by maintaining the levels of sex hormones, down regulating oxidative stress and up regulating oxidative defence. Supplementation of Vitamin D may improve the quality and function of sperm by increasing its motility and concentration.Conclusions: Although Vitamin D supplementation cannot be considered for treatment of male infertility itself, physicians should take the vitamin serum levels under consideration while providing treatment for infertile male patients.
Polymorphism of Clinical Manifestations in Patients with “the Nutcracker Syndrome”
Authors: Nesterenko Iryna Romanivna
Published: September 2021

Introduction. “The nutcracker syndrome”  occurs due to abnormal compression of the left renal vein (LRV) between the superior mesenteric artery and the aorta. Clinical manifestations range from hematuria, proteinuria, pain in the left lumbar region, left sided varicocele in men, and left sided pudendal varicosity in women to the development of severe anemia and renal failure in some cases due to progressive phlebohypertension.Materials and methods. The study included 210 patientswith suspected “nutcracker syndrome” . The age of the patients ranged from 12 to 52. All patients were interviewed for specific complaints. All referred patients  underwent color Doppler ultrasound. The patients with confirmed left renal vein stenosis underwent CT angiography.Results of the researchAccording to color Doppler ultrasound, different degree of aorta mesenteric clamp (AMC) was confirmed in 138 (65.7%) patients, critical LRV stenosis was observed in 35 of them. The predominant complaints of the patients with AMC included pain in the left half of the abdomen and left lumbar region, left sided varicocele and left sided pudendal varicosity, hematuria.. More than half of the patients with AMC complained of dysmenorrhea, and one in four patients with AMC complained of erectile dysfunction.Conclusions. There is no consensus on the diagnostic algorithm for this pathology detection. There is a lack of evidence base (multicenter clinical randomized trials) regarding the clinical selectivity of treatment approaches. The pathology is rarely diagnosed due to a number of objective and subjective reasons, nonspecific symptoms, and therefore it deserves special attention in the study of pathogenesis, diagnosis and choice of treatment approach.
The challenges of rehabilitation after COVID-19
Authors: Szymczyk Ewelina , Wolska Joanna , Wolski Dariusz
Published: September 2021

Due to the outbreak of the COVID-19 pandemic, social life and the clinical state of change of state. This disease is caused by the SARS-CoV-2 virus and is characterized by high infectivity and mortality. Due to the diversity of the tested tests, it will be difficult to obtain uniform characteristics, resulting in a uniform recovery plan for each patient. Rehabilitation, repair, execution, restoration to health, independence and reduction in value due to COVID-19.
Skin lesions caused by Orthopoxvirus, cowpox - case report from Poland
Authors: Kania Konrad , Kalicka Maria , Korzec Tomasz , Raczkiewicz Przemyslaw , Kuc Monika
Published: September 2021

Background:Despite the elimination of smallpox, other orthopoxviruses, including cowpox virus, still infect humans. Wild rodents are its natural reservoir. Infections in humans are commonly reported from contact with sick domestic cats, rarely directly from rats. Cow pox in humans is a rare zoonotic disease, the diagnosis of which is problematic due to its rarity and thus the lack of clinical experience.Case report:Presented with a summary of the available clinical data on a 15-year-old boy who became infected with cowpox by a domestic cat.The patient developed cutaneous macular changes in the facial area. Within 3 weeks of the onset of symptoms, the lesions progressed through the papular, vesicular and pustular stages before forming a hard black eschars (2 cm in diameter) with erythema and edema and regional lifadenopathy. Differential diagnosis consisting of cat scratch disease, anthrax and brucellosis excluded microbiological examination. The lesions left scars after 8 weeks of continuous topical antiseptic treatment.Conclusions:The clinical course may be complicated, and the improvement takes 4 to 8 weeks. Infection which entered through the skin changes was the cause of antibiotic therapy. Cowpox should be suspected in patients with poorly healing skin lesions accompanied by a painful black eschars with erythema and local lymphadenopathy.
Vaccination against COVID-19 in Poland
Authors: Kasperska-Dębowska Paulina Marta , Oleksy Eliza , Wojtczak Anna
Published: September 2021

Introduction. Due to the still difficult and worsening epidemic situation in Poland, related to the second wave of the coronavirus pandemic (COVID-19), it turned out to be necessary to develop, prepare and conduct additional training on the work of medical personnel during the pandemic. Preventive vaccinations and their skilful implementation play a very important role.Aim. The aim of the systematic review is to present the general principles, procedures and competences of nurses in the pandemic era, this work can be used to conduct a comparative meta-analysis.Disscusion. The vaccine protects against the symptoms of COVID-19, which has been proven in clinical trials. For both the Comirnaty vaccine and the Moderna vaccine, the European Medicines Agency website states that the effect of vaccination on the transmission of the virus is unknown and whether vaccinated people can transmit SARS-CoV-2. Clinical trials are scheduled for 2 years and, as part of conditional approval, companies will complete the data after subsequent periodic evaluations.Conclusion. Over 1.5 million people worldwide have died since the outbreak of the COVID-19 epidemic. Each vaccinated person is potentially from a few to a dozen or so people protected against infection. Already 50% of the vaccinated population will significantly reduce the risk of spreading the coronavirus in it. Vaccines are the most effective method of protection against infection with various diseases. Humanity has been successfully using this achievement of civilization for several hundred years.
Brain tumors risk factors - current state of knowledge review
Authors: Siedlecki Zygmunt , Szafrańska Małgorzata , Główczewska-Siedlecka Emilia , Śniegocki Maciej
Published: September 2021

Brain tumors cause widespread apprehension in society, associated with poor prognosis and death. Laymen most often associate them with glioblastoma multiforme which is in fact the most common malignant primary brain tumor (formerly it was considered the most common primary brain tumor, now it is thought that meningiomas are the most common). The interest of both the public and physicians is aroused by potential brain tumors risk factors. The only evidence based risk factor is ionizing radiation of head and neck. Other risk factors are also under consideration, however are not conclusive and different studies give different results. Given the widespread apprehension of brain tumors, knowledge of the risk factors seems obvious. In this manuscript, we have reviewed the current state of knowledge aboutf risk factors based on research. They confirm that apart from ionizing radiation, the existence of other risk factors is considered: cell phones, electromagnetic field, occupational exposure to raw meat, viruses. However, all these risk factors are not confirmed by reference results.
Is the determination of bone turnover markers and vitamin D useful in the diagnosis of degeneration spine disease?
Authors: Liczner Grzegorz , Wiciński Michał , Malinowski Bartosz , Cadelski Karol
Published: September 2021

Abstract: Degenerative disease of the lumbar spine is one of the most common diseases of the human musculoskeletal system and a significant public health problem. The main manifestation of degenerative spine disease is back pain, which in most cases is treated symptomatically rather than causally. The diagnosis of degenerative spine disease has been previously based on medical history and diagnostic imaging. Recently, much attention has been devoted to the biochemical indicators of bone and cartilage metabolism, which are well understood among patients with osteoporosis. Bone turnover markers indicate the metabolic activity of bone and cartilage. They occur in blood serum, urine, and synovial fluid in the form of collagen-derived proteins or enzymes, involved in the formation or resorption of bone and cartilage tissue. The study below was aimed at assessing the usefulness of determining the markers of bone turnover and cartilage damage in the blood serum of people with degenerative disease of the lumbar spine diagnosed by MRI. The biochemical diagnostics included the measurement of inflammatory parameters. The results show that the degenerative disease of the spine is local, accompanied by inflammation, and vitamin D deficiency is among the factors leading to its development.
DIAGNOSIS OF PLEOMORPHIC XANTHOASTROCYTOMA
Authors: Mikos Eryk , Dmochowska Joanna , Kanon Karol , Moqbil Sara , Góralczyk Wanesa
Published: September 2021

Introduction. Pleomorphic xanthoastrocytoma (PXA) is a rare astrocytic cancer of the central nervous system that is classified as grade II according to the WHO score. It accounts for 1% of primary brain tumors. It is mainly located in the temporal lobe and belongs to a group of tumors called long-term epilepsy associated tumors. Surgical tumor resection is the treatment of choice.

Brief description of the state of knowledge. The non-invasive method of PXA diagnostics is neuroimaging, which is based on computer tomography (CT) and magnetic resonance imaging (MRI). In the image, PXA presents as a solid tumor undergoing contrast enhancement, located supratentorial, with frequent peripheral cystic components.

The characteristic histologic picture for PXA is the presence of highly pleomorphic, fusiform or round, large astrocytes with single or multiple cell nuclei. Lymphoplasmic infiltrates are visible within the tumor. The most common mutations associated with the occurrence of this cancer are mutations in the BRAF V600E gene.

Conclusions. PXA is a very rare tumor of the central nervous system (CNS) that can recur and spread throughout the CNS. Imaging tests, i.e. CT and MRI, allow for precise imaging of the lesion, however, it is necessary to perform a histopathological examination to make a final diagnosis. The rarity of this cancer assimilates diagnostic problems. Therefore, further molecular research is needed to develop more efficient diagnostics.
Male hypogonadism – brief review of symptoms, types and ways of treatment
Authors: Tywanek Ewa , Trojanowska Paulina , Wronecki Jakub , Wiśniewska-Ślepaczuk Katarzyna , Łuczyk Robert Jan
Published: September 2021

Appropriate concentration of androgens is necessary for general men’s health, especially for development and maintain reproductive and sexual function, as well as metabolic balance. The state  of deficiency of testosterone or its inadequate action, as well as inability to produce good quality semen is called hypogonadism. Depending on the function of the testicles, production of androgens and sperm is also conditioned on hypothalamus-pituitary axis, metabolic status and age of the individual. Considering that, hypogonadism of primary, secondary, functional or late-onset origin may be recognised. As it concerns susceptible matter of sexual and reproductive health, it requires special interest of differently clinicians, i.e. endocrinologists, andrologists or urologists.
Wykorzystanie T agility Test do oceny stabilności funkcjonalnej u II-ligowych piłkarzy nożnych
Authors: Kuchciński Kacper , Szczypiór-Piasecka Karina , Mińko Alicja , Antczak Krzysztof , Orłowska Aleksandra
Published: September 2021

WSTĘP: T agility Test jest testem odpowiedzialnym za ocenę stabilności funkcjonalnej, a także poruszania wielokierunkowego. W związku z szybkością wykonanych ruchów  może zostać wykorzystany do badania zawodników różnorodnych dyscyplin sportowych, między innymi:  piłki nożnej, piłki ręcznej lub też koszykówki. Piłka nożna jako sport kontaktowy charakteryzuje się wieloma urazami nabytymi podczas treningu, czy też podczas meczu. Najbardziej narażone są stawy kończyn dolnych, takie jak: staw biodrowy, staw kolanowy i staw skokowy.

CEL: 1. Porównanie stabilności funkcjonalnej u piłkarzy nożnych drużyny II-ligowej. 2. Wpływ kontuzji na wynik T agility Test. 3.  Przydatność T agility Testu  do oceny stabilności funkcjonalnej sportowców procesu treningowego.

MATERIAŁ I METODY: Zbadano 24 zawodników profesjonalnej drużyny piłkarskiej Błękitni Stargard. Badania przeprowadzono na początku rundy jesiennej sezonu 2019/2020. Średnia wieku zawodników wynosiła 21,42 lata, średnia waga wynosiła 77 kg, średni wzrost wynosił 184 cm. Natomiast średnie BMI wynosiło 22,7. Do subiektywnej oceny stanu zdrowia zawodników posłużył kwestionariusz ankiety, z kolei do oceny funkcjonalnej wykorzystano T agility Test.

            WYNIKI: Najlepszy wynik T agility Test uzyskany w grupie badawczej wyniósł 9,1 s. Uzyskano dodatnie relacje podczas badania Korelacji Pearsona T agility Testz wiekiem, wagą, wzrostem i stażem treningowym. Test istotności w każdymz przypadków stwierdził brak istotnych różnic (p>0,999).

            WNIOSKI: 1. Na stabilność funkcjonalną u piłkarzy ma wpływ staż treningowy, im dłuższy staż treningowy tym wynik testu jest lepszy. 2. Przebyte kontuzje nie mają wpływu na osiągnięty wynik T agility Test. 3. T agility Test jest przydatny do oceny stabilności dynamicznej u sportowców.

            SŁOWA KLUCZOWE: piłka nożna, T agility Test, injuries, agility, fizjoterapia
Comprehensive rehabilitation program after knee arthroplasty of GMRS as a result of treatment of a chondrosarcoma of distal part of femur with pathological fracture of the lateral femoral condyle.
Authors: Baranowska Anna , Szczypiór-Piasecka Karina , Mińko Alicja , Antczak Krzysztof
Published: September 2021

Abstract

Introduction: Malignant neoplasms of bones and articular cartilage resulting from the operation of the mesenchymal sales cell valuation bank. Cells can differentiate in many countries. in. chondrocytes, osteoblasts or adipocytes The bone cancer that occurs is osteosarcoma. In second place is chondrosarcoma (chondrosarcoma).

Materials and methods: The work was written based on the development of a patient who had the further development of the femur part of the former cartilage sarcoma radio station. The entire treatment procedure at the Department of Orthopedics, Traumatology and Oncology of the Musculoskeletal System, located at Unii Lubelskiej 1 street in Szczecin.

Results: At the main point of treatment of the hospital clinic, the patient, the patient who returns as good working point, points to restore lost functions, as well as self-service learning.

Conclusion: Rehabilitation is an indispensable carrier of services for cancer patients. Introducing modern techniques such as therapy and osteopathy to rehabilitation, ensuring the economy of therapy.
Simplified analytical method for an anamorphic refractive shaping system of laser beams with a large aspect ratio
Authors: Tan Qin-Wen , Guo Ya-Ding , Li Yang , Zhang Lin , Shao Chong-Feng , Cui Da-Fu , Peng Qin-Jun
Published: September 2021

For reshaping aperture size and correcting low-order aberration of laser beams with large aspect ratios, a simplified analytical method is proposed to design an anamorphic refractive shaping system, which is composed of double-plane symmetric lenses. The simplified method enables performing a global study of aberrations via calculating the analytical primary wave aberration function under paraxial approximation. The aberration balance is analyzed with a three-lens laser collimating system and a compact four-lens laser expanding system. Lens bending and conic surfaces are introduced to decrease ray errors. Through the simplified analytical method, anamorphic refractive shaping systems for laser beams with large aspect ratios can be adequately analyzed and conveniently designed.
Mid-infrared optical modulator based on silicon D-shaped photonic crystal fiber with VO2material
Authors: Dawood Nada Yazeed M. , Younis B. M. , Areed N. F. F. , Hameed Mohamed Farhat O. , Obayya S. S. A.
Published: September 2021

Recently, photonic crystal fibers (PCFs) have become of significant interest due to their various applications, especially in the mid-infrared (mid-IR) regime. In this work, an optical mid-IR modulator based on silicon D-shaped PCF (Si-D-PCF) with vanadium dioxide (VO2) as a phase changing material (PCM) is presented and analyzed. Thanks to the phase transition of theVO2material between insulating (ON) and conducting (OFF) states, the modulation process can be attained. The well-known full vectorial finite element method is utilized to numerically analyze the proposed design. Further, the propagation of light through the suggested structure is studied using the 3D finite difference time domain method. The optical losses of the fundamental TM mode supported by the Si-D-PCF structure in both ON and OFF states are investigated. The obtained results reveal that the extinction ratio (ER) of the reported modulator approaches 236 dB, while the insertion loss (IL) is less than 1.3 dB over the studied wavelength range 3–7 µm at a device length (LD) of 0.5 mm. Additionally, the ER of the proposed modulator is higher than 56 dB through the whole studied wavelength range. Therefore, the proposed modulator could be utilized in photonic integrated circuits that require high ER, low IL, and large bandwidth. To the best of the authors’ knowledge, this is the first time an infrared optical modulator based on Si-D-PCF withVO2material has been presented.
Investigation of methods to extract confocal function parameters for the depth resolved determination of attenuation coefficients using OCT in intralipid samples, titanium oxide phantoms, and in vivo human retinas
Authors: Kübler Johannes , Zoutenbier Vincent S. , Amelink Arjen , Fischer Jörg , de Boer Johannes F.
Published: September 2021

The attenuation coefficient provides a quantitative parameter for tissue characterization and can be calculated from optical coherence tomography (OCT) data, but accurate determination requires compensation for the confocal function. We present extensive measurement series for extraction of the focal plane and the apparent Rayleigh length from the ratios of OCT images acquired with different focus depths and compare these results with two alternative approaches. By acquiring OCT images for a range of different focus depths the optimal focus plane difference is determined for intralipid and titanium oxide (TiO2) phantoms with different scatterer concentrations, which allows for calculation of the attenuation coefficient corrected for the confocal function. The attenuation coefficient is determined for homogeneous intralipid and TiO2 samples over a wide range of concentrations. We further demonstrate very good reproducibility of the determined attenuation coefficient of layers with identical scatter concentrations in a multi-layered phantom. Finally, this method is applied to in vivo retinal data.
Benchmarking analysis of computer generated holograms for complex wavefront shaping using pixelated phase modulators
Authors: Rothe Stefan , Daferner Philipp , Heide Sebastian , Krause David , Schmieder Felix , Koukourakis Nektarios , Czarske Jürgen W.
Published: September 2021

Wavefront shaping with spatial light modulators (SLMs) enables aberration correction, especially for light control through complex media, like biological tissues and multimode fibres. High-fidelity light field shaping is associated with the calculation of computer generated holograms (CGHs), of which there are a variety of algorithms. The achievable performance of CGH algorithms depends on various parameters. In this paper, four different algorithms for CGHs are presented and compared for complex light field generation. Two iterative, double constraint Gerchberg-Saxton and direct search, and the two analytical, superpixel and phase encoding, algorithms are investigated. For each algorithm, a parameter study is performed varying the modulator’s pixel number and phase resolution. The analysis refers to mode field generation in multimode fibre endoscopes and communication. This enables generality by generating specific mode combinations according to certain spatial frequency power spectra. Thus, the algorithms are compared varying spatial frequencies applied to different implementation scenarios. Our results demonstrate that the choice of algorithms has a significant impact on the achievable performance. This comprehensive study provides the required guide for CGH algorithm selection, improving holographic systems towards multimode fibre endoscopy and communications.
Compact fiber-ring resonator for blue external cavity diode laser stabilization
Authors: Perin Georges , Mammez Dominique , Congar Antoine , Besnard Pascal , Manamanni Karim , Roncin Vincent , Du Burck Frédéric , Trebaol Stéphane
Published: September 2021

We demonstrate a compact and low-cost all-fiber-based locking setup for frequency-noise suppression of a 420 nm external-cavity diode laser. Frequency noise reduction in the 100 Hz to 800 kHz range is demonstrated up to 40 dB associated with a linewidth narrowing from 850 kHz to 20 kHz for 10 ms integration time. This simple locking scheme might be implemented for a large range of wavelengths and can be integrated on a small footprint for embedded applications requiring narrow linewidth blue laser diodes.
High brightness silicon nanocrystal white light-emitting diode with luminance of 2060 cd/m2
Authors: Zhang Yu-Chen , Yu Zhi-Yuan , Xue Xia-Yan , Wang Fei-Long , Li Shuai , Dai Xi-Yuan , Wu Li , Zhang Shu-Yu , Wang Song-You , Lu Ming
Published: September 2021

High brightness Si nanocrystal white light-emitting diodes (WLED) based on differentially passivated silicon nanocrystals (SiNCs) are reported. The active layer was made by mixing freestanding SiNCs with hydrogen silsesquioxane, followed by annealing at moderately high temperatures, which finally led to a continuous spectral light emission covering red, green and blue regimes. The photoluminescence quantum yield (PLQY) of the active layer was 11.4%. The SiNC WLED was composed of a front electrode, electron transfer layer, front charge confinement layer, highly luminescent active layer, rear charge confinement layer, hole transfer layer, textured p-type Si substrate and aluminum rear electrode from top to bottom. The peak luminance of the SiNC WLED achieved was 2060 cd/m2. The turn-on voltage was 3.7 V. The chromaticity of the SiNC WLED indicated white light emission that could be adjusted by changing the annealing temperature of the active layer with color temperatures ranging from 3686 to 5291 K.
Modeling of speckle decorrelation in digital Fresnel holographic interferometry
Authors: Meteyer Erwan , Foucart Felix , Pezerat Charles , Picart Pascal
Published: September 2021

This paper presents analytical modeling of the speckle decorrelation noise in digital Fresnel holographic interferometry. The theoretical analysis is carried out by considering the complex coherence factor between two speckled images from two digitally reconstructed holograms at two different instants. The expression giving the modulus of the coherence factor is established and depends on the local surface deformation and parameters from the holographic setup. The analysis is supported by realistic simulations and experiments. Both simulations and experimental results exhibit a very good agreement with the theoretical prediction.
Low-cost, thermoplastic micro-lens array with a carbon black light screen for bio-mimetic vision
Authors: Baek Changhoon , Yi Jungho , Seo Jong-mo
Published: September 2021

Micro-lens array is a great example of bio-mimetic technology which was inspired by compound eyes found in insects and is used in lasers, optical communication, and 3D imaging. In this study, a micro-lens array was fabricated from cyclic olefin copolymer using a cost-effective method: compression molding and thermal reflow. Also, a light screen was installed between lenses to reduce the optical interference for clearer individual images. Cyclic olefin copolymer-based micro-lens array showed good optical results under a standard optical microscope. By placing the fabricated micro-lens array directly on an image sensor, it was observed that the light screen shows significant improvement in image quality. Also, the point spread function was analyzed to confirm the optical performance and the effectiveness of the micro-lens array with the light screen installed.
Preparation of a superhydrophobic AgNP/GF substrate and its SERS application in a complex detection environment
Authors: Liu Chundong , Lei Fengcai , Wei Yisheng , Li Zhen , Zhang Chao , Peng Qianqian , Man Baoyuan , Yu Jing
Published: September 2021

Surface-enhanced Raman scattering (SERS) is widely considered to be a fingerprint spectrum that can realize molecular identification, and it continues to receive a lot of attention due to its high sensitivity and powerful qualitative analysis capabilities. In recent years, there has been a lot of work and reports on super-sensitive SERS substrates, but often the enhanced ability of the substrate is also effective for impurities and irrelevant molecules. Therefore, a problem that still remains to be solved is how to perform effective trace detection of specific substances in a complex detection environment. Herein, a superhydrophobic Ag nanoparticle/glass microfibre filter (AgNP/GF) substrate was designed to realize the Raman detection of complex multiphase solutions. The hydrophobic three-dimensional net-like structure provides efficient Raman enhancement, making the substrate have extremely high detection limits for dye molecules and even achieving specific detection of the hexane phase component (thiram molecule) in a multiphase solution.
All-silicon, low-cross-talk terahertz waveguide crossing based on effective medium
Authors: Lees Harrison , Gao Weijie , Withayachumnankul Withawat
Published: September 2021

All-silicon effective-medium-clad waveguides are a promising candidate for an integrated terahertz platform with high efficiency and broad bandwidth. Waveguide crossings are essential circuit components, allowing for wave routing over shorter paths to increase circuit density. However, the simple intersection of two orthogonal effective-medium-clad waveguides results in terahertz wave scattering, leading to relatively high cross talk. In this work, a low-loss, 40% fractional bandwidth crossing utilizing Maxwell–Garnet effective-medium theory and wavefront planarization techniques is proposed. This monolithic structure is fabricated on a single high-resistivity float-zone silicon wafer using a deep reactive ion etching process with a modest 4.4 mm diameter (

4.03

λ
0

) structure footprint. Experimentally verified results show low insertion loss, less than 1 dB, and average cross talk level of

−

39

d
B

for both

E

11

x

and

E

11

y

operating modes, over 220–330 GHz with a 40% fractional bandwidth. This waveguide crossing can be foreseen as a useful routing component for terahertz all-silicon integrated circuits. The proposed techniques are applicable to other dielectric waveguide platforms at infrared and optical frequencies.
Nonreciprocal magnon laser
Authors: Xu Ye-jun , Song Jun
Published: September 2021

A nonreciprocal magnon laser is proposed in a compound cavity optomagnonical system consisting of an yttrium iron garnet sphere coupled to a spinning resonator. On the basis of the magnon-induced Brillouin scattering process making it possible to achieve a magnon lasing action, the Fizeau light-dragging effect caused by the spinning of the resonator further results in significant modifications in the magnon gain and the threshold power of magnon lasing for different driving directions, and then a nonreciprocal magnon laser is realized. Especially, this nonreciprocal magnon laser is highly tunable by the spinning speed and the driving direction. Our work provides an experimentally feasible pathway for manipulating spin-wave excitations and may find intriguing phenomena at the crossroad between spintronics of the magnet and nonreciprocal optics.
Single-stage few-cycle nonlinear compression of milliJoule energy Ti:Sa femtosecond pulses in a multipass cell
Authors: Daniault Louis , Cheng Zhao , Kaur Jaismeen , Hergott Jean-François , Réau Fabrice , Tcherbakoff Olivier , Daher Nour , Délen Xavier , Hanna Marc , Lopez-Martens Rodrigo
Published: September 2021

We report on the nonlinear temporal compression of mJ energy pulses from a Ti:Sa chirped pulse amplifier system in a multipass cell filled with argon. The pulses are compressed from 30 fs down to 5.3 fs, corresponding to two optical cycles. The post-compressed beam exhibits excellent spatial quality and homogeneity. These results provide guidelines for optimizing the compressed pulse quality and further scaling of multipass-cell-based post-compression down to the single-cycle regime.
The visible and near-infrared optical absorption coefficient spectrum of Parylene C measured by transmitting light through thin films in liquid filled cuvettes
Authors: Guggenheim James A. , Lyu Yuanyuan , Marques Dylan M. , Zhang Edward Z. , Beard Paul C.
Published: September 2021

Parylene C (PPXC) is a polymer deposited from the gas phase to form optically clear thin films used in devices including waveguides and sensors. The performance of these devices depends on the visible and near infrared absorption coefficient of PPXC. However, the absorption coefficient is difficult to measure. This is because PPXC films are typically too thin to exhibit detectable absorption in conventional transmittance measurements. To address this challenge, a method involving measuring the transmittance of multiple films immersed together in a liquid filled cuvette was devised. This increased the sensitivity to absorption by increasing the path length in PPXC, while also minimizing reflections and surface losses. Using 200-500 µm thick films, this method was applied to measure the absorption coefficient of PPXC at wavelengths in the range 330-3300 nm. The coefficient was found to vary spectrally by more than two orders of magnitude from 0.025 mm-1 at 1562 nm to 7.7 mm-1 at 3262 nm. These absorption measurements could aid the design of PPXC based sensors and waveguides. The method could be useful for measuring the absorption coefficient of other thin, low-loss materials, particularly those for which it is challenging to obtain thick samples such as other polymers deposited from the gas phase in a similar manner to PPXC.
CsPbBr3 perovskite quantum-dot paper exhibiting a highest 3  dB bandwidth and realizing a flexible white-light system for visible-light communication
Authors: Singh Konthoujam James , Fan Xiaotong , Sadhu Annada Sankar , Lin Chun-Ho , Liou Fang-Jyun , Wu Tingzhu , Lu Yu-Jung , He Jr-Hau , Chen Zhong , Wu Tom , Kuo Hao-Chung
Published: September 2021

We propose a flexible white-light system for high-speed visible-light communication (VLC) applications, which consists of a semipolar blue InGaN/GaN single-quantum-well micro-light-emitting diode (LED) on a flexible substrate pumping green

CsPbBr

3

perovskite quantum-dot (PQD) paper in nanostructure form and red CdSe QD paper. The highest bandwidth for

CsPbBr

3

PQD paper, 229 MHz, is achieved with a blue micro-LED pumping source and a high data transmission rate of 400 Mbps; this is very promising for VLC application. An 817 MHz maximum bandwidth and a 1.5 Gbps transmission speed are attained by the proposed semipolar blue micro-LEDs. The proposed flexible white light system and the high-bandwidth PQD paper could pave the way for VLC wearable devices.
Single-cell detection by enhancement of fluorescence in waveguides for cancer diagnosis and therapy
Authors: Dai Hailang , Shan Hongrui , Sun Zhangchi , Dai Daopeng , Shang Yuxi , Cao Zhuangqi , Chen Xianfeng
Published: September 2021

Cancer is one of the most common diseases to threaten human health. If individuals are diagnosed with malignant tumors via a single cell, medical workers are greatly advantageous to early diagnose and intervene in malignant tumors therapy. In this paper, we propose a fluorescence detection map to rapidly distinguish whether the chromosomes of a cell are normal or abnormal by detecting the fluorescent intensity of a single cell. Herein, we draw a map from a single cell with an abnormal number of chromosomes that is monitored in real time. Moreover, this way offers precise and prompt detection of the surviving of cancer cells at or near the site of the tumor after treatments for cancer, which can achieve personalized cancer diagnosis and therapy. Therefore, cancer recurrences and metastasis can be effectively identified, utilizing this ultrasensitive detection method of an abnormal chromosome number.
Virtuelle IT-Studienprojekte – Ein Erfahrungsbericht und Handlungsempfehlungen für Betreuende
Authors: Hofer Julien , Knackstedt Ralf
Published: September 2021

Der vorliegende Beitrag berichtet über die Erfahrungen eines virtuellen Studienprojekts, welches an einer deutschen Universität durchgeführt wurde. Dabei wird ein allgemeiner Überblick über die Virtualisierung von Lernen und Lehren gegeben und ein Fokus auf die agile und virtuelle Herangehensweise gesetzt. Es wird auf wichtige Aspekte der Kollaboration in virtuellen Settings eingegangen, das Setting bei einem IT-Studienprojekt allgemein beschrieben und dann ausführlich über ein konkretes, virtuelle, agiles IT-Studienprojekt in einem IT-Studiengang berichtet. Dieses Projekt befasste sich mit der Konzeption und Gestaltung eines sprachbasierten Conversational User Interfaces im Kontext von Design Thinking. Aufgrund der COVID-19-Pandemie wurde das einjährige Projekt komplett virtuell durchgeführt. Dozierender und Studierende haben also vollkommen digital mit Werkzeugunterstützung gelehrt, gelernt und gearbeitet. Mit diesem Beitrag liefern wir Erfahrungen und Anhaltspunkte, die als Basis für die Gestaltung und Durchführung anderer virtueller und agiler IT-Studienprojekte verwendet werden können. Wir ergänzen den Erfahrungsbericht schließlich mit konkreten Handlungsempfehlungen zu verschiedenen Gestaltungs- und Durchführungsaspekten, die Interessierten – Lehrenden an Hochschulen sowie Praktizierende aus Wirtschaft und Verwaltung – als Hilfestellungen dienen können.
High-integrity human intervention in ecosystems: Tracking self-organization modes
Authors: Zelnik Yuval R. , Mau Yair , Shachak Moshe , Meron Ehud
Published: September 2021

Humans play major roles in shaping and transforming the ecology of Earth. Unlike natural drivers of ecosystem change, which are erratic and unpredictable, human intervention in ecosystems generally involves planning and management, but often results in detrimental outcomes. Using model studies and aerial-image analysis, we argue that the design of a successful human intervention form calls for the identification of the self-organization modes that drive ecosystem change, and for studying their dynamics. We demonstrate this approach with two examples: grazing management in drought-prone ecosystems, and rehabilitation of degraded vegetation by water harvesting. We show that grazing can increase the resilience to droughts, rather than imposing an additional stress, if managed in a spatially non-uniform manner, and that fragmental restoration along contour bunds is more resilient than the common practice of continuous restoration in vegetation stripes. We conclude by discussing the need for additional studies of self-organization modes and their dynamics.
A more accurate method for colocalisation analysis allowing for multiple causal variants
Authors: Wallace Chris
Published: September 2021

In genome-wide association studies (GWAS) it is now common to search for, and find, multiple causal variants located in close proximity. It has also become standard to ask whether different traits share the same causal variants, but one of the popular methods to answer this question, coloc, makes the simplifying assumption that only a single causal variant exists for any given trait in any genomic region. Here, we examine the potential of the recently proposed Sum of Single Effects (SuSiE) regression framework, which can be used for fine-mapping genetic signals, for use with coloc. SuSiE is a novel approach that allows evidence for association at multiple causal variants to be evaluated simultaneously, whilst separating the statistical support for each variant conditional on the causal signal being considered. We show this results in more accurate coloc inference than other proposals to adapt coloc for multiple causal variants based on conditioning. We therefore recommend that coloc be used in combination with SuSiE to optimise accuracy of colocalisation analyses when multiple causal variants exist.
Death of an offspring and parental risk of ischemic heart diseases: A population-based cohort study
Authors: Wei Dang , Janszky Imre , Fang Fang , Chen Hua , Ljung Rickard , Sun Jiangwei , Li Jiong , László Krisztina D.
Published: September 2021

Background

The death of a child is an extreme life event with potentially long-term health consequences. Knowledge about its association with ischemic heart diseases (IHDs) and acute myocardial infarction (AMI), however, is very limited. We investigated whether the death of an offspring is associated with the risk of IHD and AMI.

Methods and findings

We studied parents of live-born children recorded in the Danish (1973 to 2016) and the Swedish (1973 to 2014) Medical Birth Registers (n = 6,711,952; mean age at baseline 31 years, 53% women). We retrieved information on exposure, outcomes, and covariates by linking individual-level information from several nationwide registers. We analyzed the abovementioned associations using Poisson regression. A total of 126,522 (1.9%) parents lost at least 1 child during the study period. Bereaved parents had a higher risk of IHD and AMI than the nonbereaved [incidence rate ratios (IRRs) (95% confidence intervals (CIs)): 1.20 (1.18 to 1.23), P < 0.001 and 1.21 (1.17 to 1.25), P < 0.001, respectively]. The association was present not only in case of losses due to CVD or other natural causes, but also in case of unnatural deaths. The AMI risk was highest in the first week after the loss [IRR (95% CI): 3.67 (2.08 to 6.46), P < 0.001], but a 20% to 40% increased risk was observed throughout the whole follow-up period. Study limitations include the possibility of residual confounding by socioeconomic, lifestyle, or health-related factors and the potentially limited generalizability of our findings outside Scandinavia.

Conclusions

The death of an offspring was associated with an increased risk of IHD and AMI. The finding that the association was present also in case of losses due to unnatural causes, which are less likely to be confounded by cardiovascular risk factors clustering in families, suggests that stress-related mechanisms may also contribute to the observed associations.