bluuebunny/crossref_metadata_2025 huggingface dataset:
Fertility in Acromegaly: A Single-Center Experience of Female Patients During Active Disease and After Disease Remission
Authors: Pirchio Rosa , Auriemma Renata S , Grasso Ludovica F S , Verde Nunzia , Garifalos Francesco , Castoro Michele , Conforti Alessandro , Menafra Davide , Pivonello Claudia , de Angelis Cristina , Minnetti Marianna , Alviggi Carlo , Corona Giovanni , Colao Annamaria , Pivonello Rosario
Published: February 2023

Context

Fertility represents a major concern in patients with acromegaly.

Objective

The current retrospective study aimed to investigate gonadal function and fertility rates in acromegalic women.

Methods

In this referral-center study, 50 acromegalic women with disease onset within reproductive age were evaluated for prevalence of gonadal dysfunction and infertility. Anthropometric, metabolic, hormonal parameters, and gynecological ultrasound were evaluated at diagnosis and after disease control. Data about menstrual disturbances, pregnancy, and polycystic ovarian morphology (PCOM) were investigated at disease onset, at diagnosis, and after disease control.

Results

At presumed disease onset, menstrual disturbances were reported in 32% of patients. Uterine leiomyoma, ovarian cysts, and PCOM were diagnosed in 18%, 12%, and 8%, respectively; 36.8% of patients were infertile. At diagnosis, menstrual disturbances were found in 58.1% (P = .02), being significantly more prevalent in patients with higher insulin-like growth factor-I quartiles (Q) (P = .03, Q1 vs Q4). Gynecological ultrasound revealed uterine leiomyoma, ovarian cysts, and PCOM in 39.1% (P = .04), 28.2% (P = .09), and 13% (P = .55), respectively. The infertility rate was 100% (P = .02). At disease control, menstrual disturbances were slightly decreased as compared to diagnosis (P = .09). Noteworthy, menstrual disturbances (P = .05) and particularly amenorrhea (P = .03) were significantly more frequent in patients with active disease duration greater than 5 years (median) as compared to those achieving disease control in less than 5 years. Among patients with pregnancy desire, 73.3% conceived at least once, with resulting infertility significantly decreased compared to diagnosis (26.7%; P = .01). At-term deliveries, preterm deliveries, and spontaneous abortions were recorded in 86.7%, 6.6%, and 6.6%, respectively, of the 15 pregnancies reported by the patients. No neonatal malformations and/or abnormalities were recorded.

Conclusion

Gonadal dysfunction and infertility are common in acromegalic women within reproductive age, being directly influenced by disease status and/or duration.
Determinants of Professional Fulfillment and Burnout Among Intensivists: A National Survey by the Society of Critical Care Anesthesiologists in 2022
Authors: Siddiqui Shahla , Warner Matthew A. , Kelly Lauren , Monteith Erika , Douin David J. , Mladinov Domagoj , Shaefi Shahzad , Stevens Robert D. , Tung Avery , Sladen Robert N.
Published: February 2023

BACKGROUND:

Increased burnout and decreased professional fulfillment among intensive care physicians is partly due to intensive care unit (ICU) workload. Although the SARS-CoV-2 (COVID-19) pandemic increased ICU workload, it also may have increased feelings of personal fulfillment due to positive public perceptions of physicians caring for COVID patients. We surveyed critical care anesthesiologists to identify the effect of provider demographics, ICU workload, and COVID-19–related workload, on professional fulfillment and burnout.

METHODS:

We performed an exploratory survey of 606 members of the Society of Critical Care Anesthesiologists (SOCCA) in January and February 2022. We used the Stanford Professional Fulfillment Index (PFI) to grade levels of professional fulfillment and markers of burnout (ie, work exhaustion and disengagement). Univariable and multivariable models were used to identify associations between provider demographics and practice characteristics and professional fulfillment and work exhaustion.

RESULTS:

One hundred and seventy-five intensivists (29%) responded. A total of 65% were male and 49% were between 36 and 45 years old. The overall median PFI score—0 (none) to 24 (most professional fulfillment)—was 17 (IQR, 1–24), with a wide distribution of responses. In multivariable analysis, factors associated with higher professional fulfillment included age >45 years (P=.004), ≤15 weeks full-time ICU coverage in 2020 (P=.02), role as medical director (P=.01), and nighttime home call with supervision of in-house ICU fellows (P=.01).

CONCLUSIONS:

Professional fulfillment and work exhaustion in this cross-sectional survey were associated with several demographic and practice characteristics but not COVID-19–related workload, suggesting that COVID-19 workload may not have either positive or negative perceptions on professional fulfillment.
Cleavage of the Jaw1 C-terminal region enhances its augmentative effect on the Ca2+ release via IP3 receptors
Authors: Kozono Takuma , Jogano Chifuyu , Okumura Wataru , Sato Hiroyuki , Matsui Hitomi , Takagi Tsubasa , Okumura Nobuaki , Takao Toshifumi , Tonozuka Takashi , Nishikawa Atsushi
Published: February 2023

Jaw1 (also known as IRAG2), a tail-anchored protein with 39 carboxyl (C)-terminal amino acids, is oriented to the lumen of the endoplasmic reticulum and outer nuclear membrane. We previously reported that Jaw1, as a member of the KASH protein family, plays a role in maintaining nuclear shape via its C-terminal region. Furthermore, we recently reported that Jaw1 functions as an augmentative effector of Ca2+ release from the endoplasmic reticulum by interacting with the inositol 1,4,5-trisphosphate receptors (IP3Rs). Intriguingly, the C-terminal region is partially cleaved, meaning that Jaw1 exists in the cell in at least two forms – uncleaved and cleaved. However, the mechanism of the cleavage event and its physiological significance remain to be determined. In this study, we demonstrate that the C-terminal region of Jaw1 is cleaved after its insertion by the signal peptidase complex (SPC). Particularly, our results indicate that the SPC with the catalytic subunit SEC11A, but not SEC11C, specifically cleaves Jaw1. Furthermore, using a mutant with a defect in the cleavage event, we demonstrate that the cleavage event enhances the augmentative effect of Jaw1 on the Ca2+ release ability of IP3Rs.
Effect of Exercise and Detraining on Signs of Puberty and Selected Inflammatory Markers in Girls with Precocious Puberty
Authors: SHOKRI BEHNAZ , HEIDARIANPOUR ALI , SHOKRI ELNAZ
Published: February 2023

Purpose

We examined the effects of aerobic exercise and detraining on adiponectin, resistin, tumor necrosis factor alpha (TNF-α), white blood cell, and pubertal signs (uterine length, ovarian volume, luteinizing hormone [LH], and follicle-stimulating hormone [FSH]) in girls with central precocious puberty (CPP).

Methods

Thirty girls with CPP (7–9 yr old) were randomly divided into CPP and CPP + Exercise (EX) groups. Fifteen healthy age-matched girls without precocious puberty participated for comparison with CPP. Subjects in the CPP + EX group attended 12 wk of aerobic exercise protocol three sessions a week. In the baseline, after completing the exercise protocol and after 4 wk of detraining, all the parameters were measured. In the CPP and healthy groups, all the parameters were measured in all three stages. To measure adiponectin, resistin, and TNF-α, the ELISA method was used. LH and FSH were measured by electrochemiluminescence immunoassay. White blood cell counts were analyzed by an automated blood cell counter. Repeated-measures ANOVA was used to analyze the results.

Results

CPP girls have lower adiponectin (P = 0.01) and higher TNF-α levels (P = 0.001) than healthy girls. In the CPP + EX group, after 12 wk, body weight and fat mass decreased, and adiponectin increased significantly (P = 0.02). Resistin (P = 0.02), TNF-α (P = 0.02), neutrophils (P = 0.01), and signs of puberty significantly (P < 0.05) decreased. After detraining, no significant change was observed except TNF-α, which increased significantly (P = 0.03). In the CPP group, no significant change was observed in any of the parameters; only LH (P = 0.0001) and uterine length and ovarian volume (P = 0.003, P = 0.001) decreased after 12 and 16 wk, respectively.

Conclusions

Aerobic exercise can have a positive effect on the state of inflammation and pubertal signs. Positive effects remain after 4 wk of detraining.
Autoimmune hepatitis in young Somalian men – experience from a German tertiary care center
Authors: Kirchner Theresa , Hartleben Björn , Köhler Sophia , Schuppert Frank , Berger Irina , Wedemeyer Heiner , Mederacke Ingmar
Published: February 2023

Background: Autoimmune hepatitis (AIH) is a rare liver disease predominantly affecting women. Data on AIH in African patients is rare. A previous study from the UK reported an unusual form of AIH in Somalian patients.

Methods: To examine whether this form of AIH can also be found in Germany, we screened the database of a major tertiary liver transplantation center.

Results and conclusions: Among 17 Somalian patients presenting to our hospital between 2008 and 2021 three male patients were admitted with liver disease. All three of them were diagnosed with AIH. Here, we present the clinical courses highlighting diagnostic challenges and the particular severity of liver disease. These cases emphasize the need to consider AIH as an important differential diagnosis in Somalian patients presenting with new onset of hepatopathy.
Impact of multiple different high-fat diets on metabolism, inflammatory markers, dysbiosis, and liver histology: study on NASH rat model induced diet
Authors: Mustika Syifa , Santosaningsih Dewi , Handayani Dian , Rudijanto Achmad
Published: February 2023

Background: The spectrum of non-alcoholic fatty liver disease (NAFLD), known as non-alcoholic steatohepatitis (NASH), can lead to advanced liver disease. It is known that a variety of diets play a significant role in the development of NAFLD/NASH. The goal of this study was to determine the most appropriate composition of diet to induce NASH in an animal model.

Methods: This research used Rattus norvegicus strain Wistar (n=27), which were divided into four groups and given each diet for 12 weeks: normal diet (ND, n=7), high-fat diet (HFD, n=6), western diet (WD, n=7) and high-fat-high-fructose diet (HFHFD, n=7). Subjects were documented for body weight. Blood samples were taken for biochemical analysis: low-density lipoprotein (LDL), triglyceride, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), hepatic lipase, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and lipopolysaccharide (LPS). Feces were taken for short-chain fatty acid (SCFA) analysis. Liver histology was analyzed using NAS (NAFLD activity score). The comparison test was carried out using the one-way ANOVA or Kruskal–Wallis test.

Results: The highest average body weight was in the WD group (346.14 g). Liver enzymes, LDL, triglyceride, propionic acid, and acetic acid in each group were not significantly different. TNF-α, IL-6, and hepatic lipase were significant (p = 0.000; p = 0.000; p = 0.004) and the highest was in the HFD group. Butyrate level was significant (p = 0.021) and the least was in the HFHFD group (4.77 mMol/g). Only WD and HFHFD had an NAS ≥ 5 (14% and 14%). The highest percentage of borderline NAS was found in WD (57%).

Conclusions: The HFD group showed significant liver inflammation but did not produce NASH histologically, whereas the WD and HFHFD groups had the potential to develop NASH because the diets affected metabolic and inflammatory parameters as well as liver histology.
The discovery of human Plasmodium among domestic animals in West Sumba and Fakfak, Indonesia
Authors: Munirah Munirah , Wahyuni Sitti , Wahid Isra , Hamid Firdaus
Published: February 2023

Background: In Indonesia, malaria incidence is at a high rate despite maximum preventive efforts. Therefore, this study aims to determine the possibility of a Plasmodium reservoir among domestic animals in malaria-endemic areas.

Methods:  Animal blood was collected using EDTA tubes, then smeared and stained with Giemsa for Plasmodium microscopic identification. About 10 µl of blood was dropped on to a filter paper to capture Plasmodium DNA. Nested PCR was used for parasite molecular detection, while Plasmodium species were identified using the sequenced DNA.

Results: A total of 208 and 62 animal blood samples were collected from Gaura village, West Sumba and Fakfak village, West Papua, Indonesia respectively. In total, 32 samples from Gaura contained P. falciparum or P. vivax, while the Plasmodium percentage in buffalo, horse, goat, and dogs were 20.7%, 14.3%, 5.8%, 16.7%, respectively. P. knowlesi was not found in any of the samples, and no other species were detected in 18 pig blood samples.

Conclusion: Human Plasmodium existence among domestic animals in Indonesia partly explains the high prevalence and persistence of malaria in some endemic areas due to a reservoir host presence. Therefore, future studies need to ascertain the cause.
Associations between the built environment, policies and curriculum in schools and primary school children’s physical activity
Authors: Emm-Collison Lydia , Salway Ruth , Matthews Joe , Reid Thomas , Jago Russell
Published: February 2023

Background: A large proportion of children in the UK do not engage in the recommended amount of physical activity. Schools are an environment where children spend a considerable portion of their time and have the potential to facilitate more physical activity. There has been little exploration of the specific school environment factors that are most pertinent to child physical activity and sedentary behaviour. This study was intended to fill this important gap.

Methods: Data were collected between March 2017 and May 2018 from 50 schools and 1223 children who participated in the B-Proact1v cohort study. School level measures were the built environment (e.g. playground equipment, cycling parking, allotments), physical activity-related policies (e.g. policy to encourage active travel) and the use of physical activity in the curriculum (e.g. regular physical activity breaks throughout day). Children’s weekday moderate-to-vigorous physical activity (MVPA) was estimated via Actigraph GT3X accelerometers. Associations between school context measures and children’s weekday MVPA were analysed using linear multilevel models, with children nested within schools, adjusted for individual characteristics.

Results: On average, children at schools with allotments, a larger amount of playground equipment and where cycle training was offered, engaged in higher levels of MVPA. PE being compromised due to space was associated with lower levels of MVPA.

Conclusions: Whilst there is a need for further exploration, the findings suggest that school-based provision and policies for active travel, sport and active play may be important to encouraging more primary school children to be more active more regularly.
Performance of Empirical Research as a Method for Achieving Professional Students’ Competence: a Case Study of Teaching Sales Skills to Future Employees of the Beauty Industry
Authors: Szczechowicz Bartosz , Kryczka Małgorzata , Alejziak Wiesław
Published: February 2023

Introduction and purpose. Didactic methods are evolving, among others, in the direction of engaging students in performance of empirical research gives rise to, in the first place, the students’ active participation in the process of knowledge creation and improves their methodological expertise. This paper presents an outlook on the value of the students’ participation in empirical research as a possibility for developing their professional competence. Material and method. A case study concerning education of the future employees of the cosmetic industry via engagement of students majoring in “cosmetology” (as part of classes forming a part of the “Sales Techniques in Cosmetology” course taught at the University of Physical Education in Kraków) in the preparation and performance of empirical research was presented. In the first place, general information pertaining to the system of educating cosmetologists in Poland and at the university in question was discussed; this offered a background for illustrating the characteristics of the aforementioned subject, with a focus on the module of classes devoted to the preparation and performance of empirical research. In the second place, the process encompassing: (1) students’ engagement in the research preparation, (2) students’ engagement in the performance of research, (3) students’ engagement in the analysis and interpretation of research results and (4) actions taken to utilize the results of research for didactic purposes, was presented. Results and conclusions. Benefits resulting from the proposed formula of teaching the subject were listed, with simultaneous reference to the diversified level of engagement of the lecturer and the students in the performance of individual stages of the research process.
Healing of peri-apical lesions with calcium hydroxide medicament following apical enlargement: a case study
Authors: Yeng Thai
Published: February 2023

With public health orders restricting movement and changes to routine endodontic practice during the COVID-19 pandemic, many patients chose to wait, in the range of 12-18 months, before returning to complete their root canal treatment. This report describes several cases of non-vital and infected teeth that showed positive healing responses from having endodontic treatment using calcium hydroxide paste as an intracanal medicament and an apical enlargement technique to further reduce bacterial numbers. This indicates healing of peri-apical lesions may occur with a longer observation period.

CPD/Clinical Relevance: Endodontic treatment for peri-apical infection may allow a patient time to decide upon treatment options.
Why does patient mental health matter? part 5: chronic orofacial pain as a consequence of psychiatric disorders
Authors: Aggarwal Vishal R , Sanger Emily , Shiers David , Girdler Jenny , Elliott Emma
Published: February 2023

This is the final article in a series looking at psychiatric presentations in dentistry. Recently, the oral health of people with severe mental illness (SMI) has gained significant media attention after the Office of the Chief Dental Officer for England published a statement on the importance of prioritizing oral health for people with SMI. Furthermore, a consensus statement has set out a 5-year plan to improve oral health in people with SMI. In Part 4, we discussed how a psychiatric disorder can result in dental pathology by contributing to risk factors associated with tooth surface loss. This article explores chronic orofacial pain symptoms and their link with psychiatry, considering the role of the primary dental care team in early recognition of psychiatric disorders. Given the range of chronic orofacial pain subtypes, we will present two separate fictionalized case-based discussions to explore their presentation.

CPD/Clinical Relevance: The primary care dental team has a role in recognition of psychiatric conditions and subsequent chronic orofacial pain.
Análisis del rótulo y características de los jabones utilizados en la piel del recién nacido
Authors: Ramos Mily C. Moreno , Veríssimo Maria de La Ó Ramallo , Velasco Maria V. Robles
Published: February 2023

Objetivo:

Analizar la información del rótulo, y las características físicas y fisicoquímicas de los jabones usados en recién nacidos (RN).

Método:

Estudio cuantitativo y descriptivo de 17 jabones comercializados en San Pablo, Brasil. Se analizó la información del rótulo (tensioactivos, pruebas de seguridad y descripción del valor de pH), y las características físicas (color y fragancia) y fisicoquímicas (valor de pH) del producto; las dos últimas, en laboratorio.

Resultados:

Se identificaron 27 tipos de tensioactivos: 70,3% (n=19) aniónicos, 18,5% (n=5) anfóteros y 11,1% (n=3) no iónicos. El 37% (n=10) tuvo un potencial moderado de irritación. En cuanto a las pruebas de seguridad, la mayoría de las formulaciones (94,1%) citó “dermatológicamente probado”. Sólo 42% citó “oftalmológicamente probado”. La translucidez estuvo presente en 23,5% (n=4) de los jabones. Todas las formulaciones presentaron fragancia. El promedio más alto de valor de pH fue de jabones en barra tradicionales (9,94 DE 0,81).

Conclusión:

Las formulaciones analizadas indicaron un potencial de irritación bajo o moderado. Cuatro jabones líquidos y uno en barra combinados tuvieron valores cercanos a los del pH de la piel del RN, y mostraron ser adecuados para la homeostasis de la barrera cutánea. Aunque las formulaciones citaron “dermatológicamente probado”, no todas citaron “oftalmológicamente probado”. Este estudio proporciona elementos para seleccionar un jabón adecuado para el RN.
Encuesta sobre la higiene de las heridas: conocimiento, implementación, obstáculos y resultados
Authors: Murphy Chris , Atkin Leanne , Hurlow Jenny , Swanson Terry , Vega de Ceniga Melina
Published: February 2023

Objetivo:

Se ha desarrollado una encuesta para comprender el conocimiento y la implementación actual del concepto de higiene de las heridas un año después de su difusión. También se analizaron los obstáculos para su implementación y los resultados.

Método:

La revista Journal of Wound Care (JWC), con la colaboración de ConvaTec, desarrolló una encuesta de 26 preguntas, compuesta por respuestas de opción múltiple y texto libre, que distribuyó globalmente por correo electrónico y en línea; la encuesta estuvo abierta unas 12 semanas. Debido a la naturaleza exploratoria de la investigación, se utilizó una técnica de muestreo no probabilístico. Los autores analizaron los resultados de la encuesta para sacar conclusiones de los datos.

Resultados:

Un total de 1478 participantes dio su consentimiento para el uso de sus datos combinados anonimizados. Casi el 90% era de Estados Unidos o el Reino Unido. La mayoría se desempeñaba como especialista en el cuidado de las heridas y estaba distribuido equitativamente entre centros de atención primaria y hospitales de agudos. El 66,6% había trabajado en el área de cuidado de las heridas durante más de 8 años. Los encuestados trabajaban con una amplia variedad de tipos de heridas. Más de la mitad (57,4%) había oído hablar del concepto de higiene de las heridas, y entre ellos, el 75,3% la había implementado; el 78,7% respondió que la aplicaba “siempre”, mientras que el 20,8% lo hacía “a veces”. Los tres principales obstáculos para su adopción fueron la confianza (39,0%), el deseo de que haya más estudios sobre la higiene de las heridas (25,7%) y la competencia (24,8%). En general, tras la implementación de la higiene de las heridas, el 80,3% informó que las tasas de cicatrización de sus pacientes habían mejorado.

Conclusión:

Los encuestados estuvieron totalmente de acuerdo en que la implementación de la higiene de las heridas es un método exitoso para el tratamiento del biofilm y un componente fundamental para mejorar las tasas de cicatrización en heridas de difícil cicatrización. Sin embargo, los obstáculos para su adopción e implementación demuestran que se necesitan cursos integrales de educación y capacitación, apoyo institucional para los cambios de política, protocolos, y más estudios clínicos para promover la higiene de las heridas.
A New Level of Control
Authors: Foukner Jiri
Published: February 2023

A COMBINATION OF THE LATEST ADVANCED MOBILE VALVE, CONTROL AND SOFTWARE TECHNOLOGIES CAN SOLVE EVEN THE MOST COMPLEX OF MACHINE CHALLENGES, IN A SHORT PERIOD OF TIME
Secure Connections
Authors: Koenig Nadja
Published: February 2023

A NEW RANGE OF FLAT-FACE, QUICK-RELEASE COUPLINGS HAS BEEN DESIGNED ESPECIALLY FOR USE IN CONSTRUCTION MACHINERY
Reimagining Telematics
Authors: McGuirk Finn
Published: February 2023

A VERSATILE TELEMATICS AND CONNECTIVITY PLATFORM IS ENABLING IN-CAB DISPLAYS, CONTROLLERS OR DEDICATED TELEMATICS MODULES TO BE DEPLOYED, SO THAT OPTIMIZED IOT SOLUTIONS CAN BE REALIZED FOR A WIDE RANGE OF APPLICATIONS
Ivt Expo February 13-14, 2019 - Cologne, Germany
Authors: Verpraet Illya
Published: February 2023

ANYONE INVOLVED IN BUILDING OR SPECIFYING AN INDUSTRIAL VEHICLE NEEDS TO BE AT iVT EXPO. LEADING SUPPLIERS WILL SHOWCASE THE LATEST COMPONENTS AND TECHNOLOGY IN A NEW EXHIBITION ALONGSIDE A CONFERENCE FEATURING WORLD-RENOWNED EXPERTS PRESENTING ON THE KEY AREAS OF DEVELOPMENT THAT MATTER MOST. IF YOU WANT TO BE AHEAD OF THE GAME, YOU CAN'T AFFORD TO MISS THIS!
Powering Ahead
Authors: McCullough Chris
Published: February 2023

JOHN DEERE'S NEW 9000 SERIES IS POSSIBLY THE MOST POWERFUL RANGE OF SELF-PROPELLED FORAGE HARVESTERS EVER PRODUCED – THANKS IN NO SMALL PART TO A NEW PARTNERSHIP WITH LIEBHERR ENGINES
Combating the Cold
Authors: Bazlen Leonhard
Published: February 2023

THE LATEST HEATING TECHNOLOGY PROVIDES A QUIET, EFFICIENT AND RELIABLE WAY TO KEEP VEHICLE CABS COMFORTABLE IN EXTREME CONDITIONS, WHILE WATER HEATERS CAN HELP PREHEAT MOTORS AND CLEAR ICE FROM WINDOWS
Operator-Assist Extras
Authors: Boudreau Jeanine
Published: February 2023

A SHORTAGE OF SKILLED LABOR IN THE CONSTRUCTION INDUSTRY IS A CHRONIC PROBLEM, BUT DESIGN ENGINEERS CAN BUILD IN TECHNOLOGIES THAT CAN OVERCOME THE ISSUE
Natural Efficiency
Authors: Willis Paul
Published: February 2023

Engineers that draw inspiration from nature are developing and testing their ideas through digital modeling and experimentation
Innovate to Get Ahead
Authors: Wheatley Malcolm
Published: February 2023

An increase in research and development is a key part of the government’s Industrial Strategy - but it will only be achieved if manufacturers take a longer-term approach
Around the Regions: Yorks & the Humber
Authors: Smith June
Published: February 2023

Manufacturers in Yorkshire and the Humber are positive as 2018 continues into the summer, with many reporting record-breaking sales. However, the threat of Brexit looms large, says EEF, the manufacturers’ organisation, in our latest regional report
The Price is Right
Authors: Roper Jack
Published: February 2023

Network Rail and partners reflect on the many lessons that were learned during the costly Great Western electrification project, and reveal new approaches being taken to accelerate the decarbonization of the UK’s railway network at a more affordable rate
Fiber optic temperature and strain sensor using dual Mach–Zehnder interferometers
Authors: Li Yousong , Jiang Yichao , Tang Nan , Wang Guanling , Tao Jiali , Zhang Gang , Ge Qiang , Zhang Ningjuan , Wu Xuqiang
Published: February 2023

A fiber optic temperature and strain sensor using dual Mach–Zehnder interferometers (MZIs) is proposed. The dual MZIs were fabricated by fusion splicing of two different fibers between two single-mode fibers. The two fibers of thin-core fiber and small-cladding polarization maintaining fiber were fusion spliced with a core offset. As the responses of the two MZIs are different in terms of temperature and strain, simultaneous temperature and strain measurement were experimentally validated by selecting two resonant dips in the transmission spectrum to construct a matrix. Experimental results show that the proposed sensors had the maximum temperature sensitivity of 66.67 pm/°C and the maximum strain sensitivity of −2.0pm/µε. The minimum discriminated temperature and strain of the two proposed sensors were 0.20°C and 0.71 µε, and 0.33°C and 0.69 µε, respectively. The proposed sensor has promising application prospects due to the merits of ease of fabrication, low costs, and good resolution.
NASA Research Requirements for Atmospheric Observations
Authors: Theon J. S.
Published: February 2023

Observations of the atmosphere and its underlying surfaces (land and oceans) by space-based sensors have already made significant contributions to our understanding of atmospheric behavior. However, with one or two exceptions, these sensors have been passive in design and have therefore been subject not only to restrictive limitations in horizontal and vertical resolution, but in accuracy. Inversion schemes necessary to convert the measured radiances to a useful atmospheric parameter, a temperature profile for example, contribute to further degradation in the accuracy of the measurement.
Scanning CO2 Laser Doppler Anemometers for Ground-Based and Airborne Applications
Authors: Lennon C. M.
Published: February 2023

Long-range, scanning CO2 laser Doppler anemometers are described. Experimental measurements are compared with theory and conventional anemometers. A helicopter-borne low-airspeed sensor is proposed.
Classification and Characteristics of Coherent Lidar Systems
Authors: Lading Lars , Hanson Steen
Published: February 2023

Coherent Lidars have almost become synonymous with CO2 laser systems with heterodyne detection. However, any lidar system operating close to the diffraction limit could be called "coherent". Conventional lidars based on e.g. Ruby or YAG laser are not in this category. In contrast, most systems for wind measurements are based on a diffraction-limited performance. The measuring range of coherent lidars is often in the near field, which may extend up to 100 km. The range resolution can then be determinated by focusing.
Test of an Airborne Differential Reflection CO2-Laser System to Measure Soil Parameters
Authors: Remus G. , Werner Ch. , Wilckens V. , Lehmann F. , Wiesemann W. , Englisch W.
Published: February 2023

During the last few years the CO2-laser heterodyne system DIALEX has been used in the DFVLR-twin engined aircraft DO 28 to measure atmospheric water vapor and trace gases (SF6) (Wiesemann and Rother 1982). Laboratory measurements of soil reflectance show some significant wavelength dependency (Shumate et al., 1981, Boscher and Lehmann 1980).
Speckle Statistics of Atmospherically Backscattered Laser Light
Authors: Yura H. T. , Churnside J. H.
Published: February 2023

In a number of remote sensing applications, a laser pulse is transmitted into the atmosphere where it is scattered by aerosol particles. The backscattered portion is collected by the receiver and the detected signal is processed to obtain the quantity of interest.(1,2) Since atmospheric aerosols are typically separated by many wavelengths of the illuminating light, laser speckle can be observed in the backscattered signal. A number of physical processes combine to determine the characteristics of the aerosol speckle pattern. The most important of these are discussed, along with their effects on the correlation properties of the backscattered light.
Atmospheric Aerosol Backscatter Measurements Using a Tunable Coherent CO2 Lidar
Authors: Menzies R. T. , Kavaya M. J. , Flamant P. H. , Haner D. A.
Published: February 2023

An experimental study is underway to determine the range of variability of atmospheric aerosol backscatter over the Pasadena, CA region, using a coherent CO2 lidar at several wavelengths between 9.25 μm and and 10.6 μm. Measurements of vertical profiles of aerosol backscatter have been conducted thus far at the 10P(20) and 9P(20) lines, at 10.6 μm and 9.5 μm, respectively, using a calibration technique which includes measurement of the return signal from a hard target (flame-sprayed aluminum) positioned at a range of 2 km from the lidar. Operation of the lidar at the 9R(22) line, at 9.26 μm, in order to gather comparative aerosol backscatter profile data at 9.26 μm and 10.6 μm, is in progress.
Atmospheric Aerosol Profiles at CO2 Wavelengths
Authors: Post Madison J.
Published: February 2023

In 1980, NOAA constructed a coherent, pulsed, Doppler lidar1 and reported2 early results of aerosol backscattering at λ = 10.6 μm. Since that time, considerably more data have been taken, processed, and archived at WPL in Boulder to form a data base that can be analyzed statistically. The results of such an analysis are presented here.
Vertical Atmospheric Extinction Profiles Measured with Lidar
Authors: Kunz G. J. , Lamberts C. W. , Bakker T.
Published: February 2023

Vertical structure information can be acquired by performing lidar measurements under positive elevation angles. [1-9]. Problems are encountered in inverting these data because a relation between extinction and backscatter is required in order to obtain a unique solution of the lidar equation. Besides a boundary condition is needed at any distance within the range of the lidar signal. Error analysis proves that zeroes and singularities in the solution are avoidable when the inversion is started at the end of the measurement track [9]. The solution converges to the real extinction at smaller distances. This convergence occurs faster when the optical depth is larger. A disadvantage of this method is that the boundary value has to be estimated or calculated at a point where the signal to noise ratio is small, leading to inaccurate values.
Heterodyne Lidar for Monitoring Aerosols
Authors: Montgomery W. W.
Published: February 2023

A cw heterodyne lidar system operating at 10.6 μm, that determines the concentration of aerosols has been developed and is described with experimental data.
FAA Requirements for Improved Meteorological Information Optical Society of America, August 2, 1983, Aspen, Colorado
Authors: Blake Neal A.
Published: February 2023

In 1981, the federal aviation administration (FAA) developed a modernization plan for the national airspace system (NAS) which included a significant increase in funds for programs related to the observation and dissemination of weather. In that same year, administrator helms initiated a national airspace review (NAR) with participation from the user community. The review covered many areas including aviation weather services where 26 recommendations for improvement were made. These recommendations are being studied as a part of the process of updating the FAA aviation weather plan. One of the recommendations, which was also made by a congressional committee, urged the establishment of a focal point for weather in FAA. This resulted in the establishment of the FAA weather coordination program office in 1982. This office has initiated a full review of aviation weather requirements and, under the sponsorship of the federal coordinator's office, a governmentwide review of all weather programs relating to aviation weather services was recently conducted. A revised aviation weather plan is scheduled for publication this fall.
Airborne Applications of Coherent Laser Radar
Authors: Woodfield Alan A , Vaughan J Michael
Published: February 2023

The Laser True Airspeed System (LATAS) developed by the RAE and RSRE and installed on the RAE HS125 research aircraft has proved exceptionally reliable and rugged. During over two years of varied flight trial experience the experimental equipment has never needed any special treatment. Optical readjustment has only been required on fitting a new laser; the latest installation has been in place 14 months with an average of two flights per week. This demonstrates that commercial ‘fit and forget’ CW Doppler Laser systems are now a practical proposition within the present state of the art.
Coherent Doppler Wind Measurements Using Neodymium Lasers
Authors: Kane T.J. , Byer R.L.
Published: February 2023

The value of remote wind sensing systems based on carbon dioxide lasers is well established. Coherent LIDAR systems have been constructed and have successfully measured the depth resolved doppler shift of radiation at 10.6 microns.1,2 The high atmospheric transmissivity and the relatively small loss of coherence due to atmospheric turbulence at the CO2 wavelength make it unlikely that another wavelength will be chosen for atmospheric reasons alone.
Intrapulse Frequency Sweeping in CO2 TEA Lasers
Authors: Willetts D V , Harris M R
Published: February 2023

Frequency chirps within the output pulse of CO2 lasers limit their usefulness in coherent detection systems. We present an in-depth study of the mechanisms responsible for the intrapulse chirp, so that it may be controlled by suitable laser design. Since on the timescale of a few μs the resonator is mechanically rigid (see below), these frequency variations must arise from refractive index changes within the cavity. Such changes may arise from laser action1 as well as from discharge induced effects2,3; to avoid confusion the processes associated with the discharge are described first by observing refractive index changes in CO2-free discharges which cannot lase under our experimental conditions. The method used was to insert the TEA discharge within the resonator of a cw CO2 laser whose operating frequency was monitored by heterodyning with a cw CO2 local oscillator. The index changes arising within the discharge thus give rise to frequency changes exactly as would result from the same phenomena in a TEA laser. The beat signal is recorded and the temporal variation of beat frequency extracted from the positions of the zero crossings.
1000 Hz Mini-TEA CO2 Laser*
Authors: Brown Robert T.
Published: February 2023

This paper describes a high-repetition-rate pulsed CO2 laser which is presently being fabricated at the United Technologies Research Center for delivery to the Los Alamos National Laboratory for use in photochemistry studies. The major design goal of the program is to produce 100 mJ per pulse in a single-transverse-mode, 100 nsec gain-switched spike on the 10P(20) CO2 laser transition at repetition rates to 1000 Hz. The operating characteristics of this laser are compatible with those required for frequency-stable laser radar systems for remote wind sensing, remote species detection, and for tracking and ranging.
Doppler Spectrum Estimates
Authors: Groginsky Herbert L.
Published: February 2023

Current status of analog SAW technology and digital algorithms such as pulse pair, poly pulse pair, maximum likelihood and maximum entropy spectral parameter estimators are discussed.
Variable Fringe Spacing Laser Doppler Velocimeter
Authors: Tedjojuwono K. , Kawase Y. , Asakura T.
Published: February 2023

A laser Doppler velocimeter (LDV) is applied in many fields to observe moving particles or fluid which conveys them1. The field to be searched may be in the microscopic as well as in the atmospheric scale. Though there are various optical arrangements of the LDV, their essential structures can be classified into two main groups, i.e. the reference type and the differential (real fringe) type velocimeters.
Wind Measurement Accuracy of the NOAA Pulsed, Infrared, Doppler Lidar
Authors: Hall F. F. , Huffaker R. M. , Hardesty R. M. , Jackson M. E. , Lawrence T. R. , Post M. J. , Richter R. A. , Weber B. F.
Published: February 2023

We have measured wind fields from the atmospheric boundary layer to the lower stratosphere using the NOAA pulsed, infrared (CO2) Doppler lidar and compared the results with measurements by sonic anemometers on a 300 m tower, by rawinsondes, by Jimspheres, and by a radar wind profiler. Lidar-measured winds were determined using a velocity azimuth display or VAD method (Lhermitte and Atlas, 1961). The results show that when the backscattered signal exceeds lidar system noise by 10 dB, wind measurement is accurate to within a small fraction of a meter per second. In this paper, we discuss how these comparisons were made and point out other features of measuring wind fields with pulsed Doppler lidars.
Dual-Doppler Analysis of Lidar Measurements Taken during JAWS
Authors: Rothermel Jeffry , Hardesty R. Michael , Kessinger Cathy
Published: February 2023

The Joint Airport Weather Studies (JAWS) Project conducted a field investigation during the summer of 1982 in and around Denver, Colorado. The principal objective of JAWS was to study convectively driven downdrafts and resulting outflows near the earth's surface. In general, information on wind fields was collected in several ways, including the use of Doppler radars, instrumented aircraft and rawinsondes. In particular, JAWS was marked by the participation of two ground-based CO2, 10.6 µm Doppler lidars, one operated by NASA/Marshall and the other by NOAA/WPL. Observations of surface winds (as well as other parameters) in the area of the lidars were made routinely using 27 Portable Automated Mesonet (PAM) stations operated by the National Center for Atmospheric Research (NCAR). Figure 1 shows the location of the lidars, PAM stations and Doppler radars (CP–2, CP–3 and CP–4, operated by NCAR).
A Pulsed CO2-Laser heterodyne Radar for Simultaneous Measurements of Range and Velocity
Authors: Malota F.
Published: February 2023

To measure simultaneously the range and velocity of solid targets, a pulsed heterodyne detection technique can be used. An advantage of heterodyne detection over direct detection is that the signal-to-noise ratio is higher in heterodyne than in direct detection. Measured values of the heterodyne-to-direct advantage are between 100 and 150, although theoretical values are much higher.
Solid State Laser Technology for Coherent Lidar
Authors: Allario Frank , Byvik Charles E. , Barnes Norman P.
Published: February 2023

As part of the National Aeronautics and Space Administration's (NASA) Space Station program, a lidar facility is being planned to conduct a series of scientific experiments from a polar orbiting platform. The thrust of these experiments is to improve our understanding of atmospheric chemistry and dynamics, altimetry, and meteorology. A number of scientific experiments were recently developed by a panel of scientists and lidar technologists and included both atmospheric backscatter (Lidar) and Differential Absorption and Lidar (DIAL) experiments. The major investigations to be conducted include measurements of the vertical profiles of atmospheric aerosols, the height of the Planetary Boundary Layer (PBL), the distribution of cirrus clouds, vertical profiles of water vapor in the lower and upper atmosphere, vertical profiles of ozone, and measurements of the vertical profiles of pressure and temperature. These experiments were developed by the Lidar Atmospheric Sounder and Altimetry (LASA) panel, and have been summarized in a NASA document.
Small Signal Gain and Vibrational Relaxation for 13CO2*
Authors: Kroeker David , DeFaccio Mark , Pindroh Albert , Guyer Dean , Fisher Charles
Published: February 2023

Because of the interest in CO2 isotopes for laser applications involving atmospheric propagation, we have determined the small signal gain for 13CO2 and compared the results with measurements for 12CO2 under identical pumping conditions. Previous work with low pressure cw lasers found that the small signal gain for 13CO2 was ≈60% of that for 12CO2.(1) Small signal gain measurements have not been reported for high pressures, but similar energies have been obtained from a TEA laser using both 13CO2 and 12CO2 gas mixes.(2) Absorption measurements indicate that the 00°1 - (10°0 + 02°0)I transition probability is higher for 13CO2,(3) which would result in higher small signal gain, if the inversion density is the same. Because of this conflicting information, it is difficult to design an amplifier operating with 13CO2. Therefore, we have measured the small signal gain for both 13CO2 and 12CO2 for the same pumping conditions.
The Mode-medium Interaction in Pulsed CO2 Lasers
Authors: Smithers Martin E.
Published: February 2023

The mode-medium interaction (MMI) in pulsed carbon-dioxide lasers results from the laser-induced medium perturbation (LIMP) effect. 1 The LIMP effect is due to the faster vibration-translation (V-T) deactivation rate of the lower laser level compared to that of the upper laser level. Thus the rate of kinetic heating is affected by the presence of stimulated emission. Treating the lasing modecules as 3- level systems, and assuming that the lower level is deactivated essentially instantaneously, the volumetric heating rate Q is given by where v2/v = 2.44 and v1/ v=1.47 for lasing at 10.64 μm, g is the gain per unit length, IS is the saturation intensity and I is the intensity. In Eq. (1) the first term results from collisions, and the second term, from stimulated emisssion.
Heterodyne Efficiency of Quadrant Detectors
Authors: Tucker Walter , Barrett John L.
Published: February 2023

Considerable work has been done on heterodyne efficiency of optical detectors1-6. Properties considered have been beam spot size, phase front alignment and detector uniformity. Efficiencies have been evaluated using combinations of Planar, Airy, and Gaussian signal and local oscillator fields. Previous work has dealt with circular, single detectors.
CO2 Heterodyne Detection with Acousto-optical Modulation
Authors: Minjia Pi , Yongjiang Dai , Haipeng Yu , Dongsong Sun
Published: February 2023

The choice of transmitter waveform shows that the approach of the FM-CW can provide high accuracy and resolution measurement of ranges and velocities of a target. The laser beam modulation has obtained successfully in a Bragg device.
MAPM: A Coherent CO2 Dial System
Authors: Grant William B.
Published: February 2023

The Mobile Atmospheric Pollutant Mapping System (MAPM) has been developed and demonstrated at JPL with funding from the U. S. Air Force. MAPM was designed around a pair of hybrid TEA CO2 lasers to enable DIAL measurements to be made rapidly, to long range, and with high accuracy. This paper will describe the system, discuss the data processing algorithms, present some data on signal averaging, on concentrations of water vapor and trace molecular species, as well as review the literature on the water vapor absorption coefficients at CO2 laser line frequencies.
Accuracy of Temperature Measurements Using High Spectral Resolution Lidar
Authors: Krueger David A. , She C. Y.
Published: February 2023

The High Spectral Resolution LIDAR (HSRL) technique has been proposed (1,2) to measure the temperature profile in the atmosphere with a resolution of 1°K in real time with a spatial resolution of 15 to 30 m. A 10-nanosecond pulse centered on frequency, vL, is sent into the atmosphere. The returning light is split and each beam is passed through one of two very narrow atomic vapor filters centered on vF, but with slightly different band widths corresponding to different vapor temperatures. Tuning the laser frequency to coincide with the center of the filter will remove the strong central aerosol scattering peak. The transmitted light is that scattered by the air molecules at a range determined by the time delay. The ratio of these two signals is then compared to that calculated from kinetic theory (3,4) for different temperatures.
Imaging Coherent CO2 Laser Radar
Authors: Renhorn Ingmar , Letalick Dietmar , Steinvall Ove
Published: February 2023

It has been an increased demand on sensor performance and multisensor processing in the modern battlefield. The rapidly growing electro-optic technology, manifested in e.g. image intensifiers, thermal imagers and range finders, has improved the overall performance with respect to all-time, all-weather operations. Still, high false alarm rates and poor recognition capabilities are critical issues that now are addressed by multisensor concepts. The coherent laser radar can give additional observables that can improve on the analysis substantially. New type of information will also make extended operations possible.