bluuebunny/crossref_metadata_2025 huggingface dataset:
Preliminary results from a phase II study of tislelizumab combined with radiotherapy as bladder-preserving treatment for patients with high-risk non-muscle-invasive bladder cancer (HR NMIBC) unresponsive to bacillus Calmette-Guerin (BCG).
Authors: Li Zhiyong , He Liru , Li Xiangdong , Yao Kai , Liu Yang , Qin Zike , Ye Yunlin , Zhou Fangjian , Liu Zhuowei
Published: February 2023

510

Background: Radical cystectomy (RC) was recommended to patients (pts) with HR NMIBC BCG-unresponsive papillary tumors. Clinical unmet need was to explore non-surgical treatment options for pts who were ineligible for or refused RC. Our study aimed to evaluate the efficacy and safety of tislelizumab combined with radiotherapy as bladder-preserving treatment for pts with HR NMIBC unresponsive to BCG. Methods: This open-label, single arm phase II study enrolled pts with HR NMIBC BCG-unresponsive papillary tumors (high-grade Ta or T1 tumors without carcinoma in situ). The papillary tumors should be removed all visible lesions by transurethral resection of bladder tumor (TURBT). Within 2 weeks after TURBT, eligible pts received tislelizumab 200 mg in day 1 (D1), every 21 days for eight cycles and a total radiotherapy dose of 60-66 GY in 30-33 fractions over seven weeks. The primary end point was disease-free survival (DFS) rate at 12 months (defined as no reappearance of high grade or T1 tumors or clinical stage development after the therapy). Secondary end points were bladder-preservation rate, OS and safety. Our study anticipated a DFS rate at 12 months was 45% and the study would enroll 32 pts to meet the primary endpoint. Results: By Sep. 2022, 14 eligible pts were enrolled. Ten pts have completed therapy and were analyzed (male 90.0%; median age 58 years (31-79); pure TCC 100%; median tumor size 1.0 cm (0.5-2.0); 40% multiple papillary tumours; median eGFR, 91.1 mL/(min•1.73m2) (46.1-115.5); high-grade Ta 40.0%, T1 60.0%; median of 11 previous BCG instillations (9-19)). Median follow-up was 20.3 months (9.9-28.1), the median number of tislelizumab cycles was 8 (2-8) and radiotherapy doses was 60 GY (60-66) in 30 fractions. The DFS rate at 12 month was 80.0% (95%CI, 67.4%-92.6%), at 24 month was 60.0% (95%CI, 40.3%-79.7%). Two pts showed reappearance of high-grade Ta and received TURBT, one patient showed stage development from T1N0M0 to M1 disease and received systemic treatment. The bladder-preservation rate at 24 months was 100% (95%CI, 100%-100%). The OS rate at 24 months was 100% (95%CI, 100%-100%). Treatment related adverse events (TRAEs) of any grade were rash (40.0%), neutropenia (10.0%), hyperthyroidism (10.0%), AST/ALT increased (10.0%) and hyperglycaemia (10.0%). 5 pts experienced immune related AEs, including rash (n=4, G1-2), hyperthyroidism (n=1, G2), hyperglycaemia (n=1, G3) and AST/ALT increased (n=1, G3). Conclusions: Our preliminary results supported the use of tislelizumab combined with radiotherapy as a promising bladder-preserving therapy for pts with BCG-unresponsive HR NMIBC who were ineligible for or refused RC. Clinical trial information: ChiCTR2000035275 .
Assessment of Puberty and Hypothalamic–Pituitary–Gonadal Axis Function After Childhood Brain Tumor Treatment
Authors: Rosimont Manon , Kariyawasam Dulanjalee , Samara-Boustani Dinane , Giani Elisa , Beltrand Jacques , Bolle Stephanie , Fresneau Brice , Puget Stephanie , Sainte-Rose Christian , Alapetite Claire , Pinto Graziella , Touraine Philippe , Piketty Marie-Liesse , Brabant Séverine , Abbou Samuel , Aerts Isabelle , Beccaria Kevin , Bourgeois Marie , Roujeau Thomas , Blauwblomme Thomas , Rocco Federico Di , Thalassinos Caroline , Rigaud Charlotte , James Syril , Busiah Kanetee , Simon Albane , Bourdeaut Franck , Lemelle Lauriane , Guerrini-Rousseau Léa , Orbach Daniel , Doz François , Dufour Christelle , Grill Jacques , Polak Michel , Briceño Laura González
Published: February 2023

Context

Endocrine complications are common in pediatric brain tumor patients.

Objective

To describe hypothalamic–pituitary–gonadal axis (HPGA) function in patients treated in childhood for a primary brain tumor more than 5 years earlier, in order to identify risk factors for HPGA impairment.

Methods

We retrospectively included 204 patients diagnosed with a primary brain tumor before 18 years of age and monitored at the pediatric endocrinology unit of the Necker Enfants-Malades University Hospital (Paris, France) between January 2010 and December 2015. Patients with pituitary adenoma or untreated glioma were excluded.

Results

Among patients with suprasellar glioma not treated by radiotherapy, the prevalence of advanced puberty was 65% overall and 70% when the diagnosis occurred before 5 years of age. Medulloblastoma chemotherapy caused gonadal toxicity in 70% of all patients and in 87.5% of those younger than 5 years at diagnosis. In the group with craniopharyngioma, 70% of patients had hypogonadotropic hypogonadism, which was consistently accompanied by growth hormone deficiency.

Conclusion

Tumor type, location, and treatment were the risk main factors for HPGA impairment. Awareness that onset can be delayed is essential to guide information of parents and patients, patient monitoring, and timely hormone replacement therapy.
Five-year Weight Loss Maintenance With Obesity Pharmacotherapy
Authors: Weintraub Michael A , D’Angelo Debra , Tchang Beverly G , Sahagun Ageline D , Andre Clarissa , Aronne Louis J , Shukla Alpana P
Published: February 2023

Context

Long-term treatment of obesity with lifestyle changes alone is unsustainable for most individuals because of several factors including adherence and metabolic adaptation. Medical management of obesity has proven efficacy for up to 3 years in randomized controlled trials. However, there is a dearth of information regarding real-world outcomes beyond 3 years.

Objective

This work aimed to assess long-term weight loss outcomes over a 2.5- to 5.5-year period with US Food and Drug Administration (FDA)-approved and off-label antiobesity medications (AOMs).

Methods

A cohort of 428 patients with overweight or obesity were treated with AOMs at an academic weight management center with an initial visit between April 1, 2014, and April 1, 2016. Intervention included FDA-approved and off-label AOMs. The primary outcome was percentage weight loss from initial to final visit. Key secondary outcomes included weight reduction targets as well as demographic and clinical predictors of long-term weight loss.

Results

The average weight loss was 10.4% at a mean follow-up duration of 4.4 years. The proportions of patients who met the weight reduction targets of 5% or greater, 10% or greater, 15% or greater, and 20% or greater were 70.8%, 48.1%, 29.9%, and 17.1%, respectively. On average, 51% of maximum weight loss was regained, while 40.2% of patients maintained their weight loss. In a multivariable regression analysis, a higher number of clinic visits was associated with more weight loss. Metformin, topiramate, and bupropion were associated with increased odds of maintaining 10% or greater weight loss.

Conclusion

Clinically significant long-term weight loss of 10% or more beyond 4 years is achievable in clinical practice settings with obesity pharmacotherapy.
Morbidity Associated With Primary Hyperparathyroidism—A Population-based Study With a Subanalysis on Vitamin D
Authors: Soto-Pedre Enrique , Lin Yeun Yi , Soto-Hernaez Jimena , Newey Paul J , Leese Graham P
Published: February 2023

Context

Primary hyperparathyroidism (PHPT) is associated with increased risk of morbidity and death, and vitamin D levels are a potentially confounding variable.

Objective

The aim of this study was to assess morbidity and mortality associated with primary hyperparathyroidism (PHPT).

Methods

In this population-based retrospective matched cohort study, data linkage of biochemistry, hospital admissions, prescribing, imaging, pathology, and deaths was used to identify patients across the region of Tayside, Scotland, who had PHPT from 1997 to 2019. Cox proportional hazards models and hazards ratios (HR) were used to explore the relationship between exposure to PHPT and several clinical outcomes. Comparisons were made with an age- and gender-matched cohort.

Results

In 11 616 people with PHPT (66.8% female), with a mean follow-up period of 8.8 years, there was an adjusted HR of death of 2.05 (95% CI, 1.97-2.13) for those exposed to PHPT. There was also an increased risk of cardiovascular disease (HR = 1.34; 95% CI, 1.24-1.45), cerebrovascular disease (HR = 1.29; 95% CI, 1.15-1.45), diabetes (HR = 1.39; 95% CI, 1.26-1.54), renal stones (HR = 3.02; 95% CI, 2.19-4.17) and osteoporosis (HR = 1.31; 95% CI, 1.16-1.49). Following adjustment for serum vitamin D concentrations (n = 2748), increased risks for death, diabetes, renal stones, and osteoporosis persisted, but not for cardiovascular or cerebrovascular disease.

Conclusion

In a large population-based study, PHPT was associated with death, diabetes, renal stones, and osteoporosis, independent of serum vitamin D concentration.
Insulin-Like Growth Factor 1 and Risk of Cardiovascular Disease: Results From the UK Biobank Cohort Study
Authors: Lin Jiayang , Yang Linjie , Huang Junlin , Liu Yating , Lei Xuzhen , Chen Ruxin , Xu Bingyan , Huang Chensihan , Dou Weijuan , Wei Xueyun , Liu Deying , Zhang Peizhen , Huang Yan , Ma Zhimin , Zhang Huijie
Published: February 2023

Context

Relationships between insulin-like growth factor 1 (IGF-1) levels and cardiovascular disease (CVD) in the general population remain unclear.

Objective

This study aims to investigate the association of circulating IGF-1 concentrations with CVD from a population-based cohort study.

Methods

A total of 394 082 participants without CVD and cancer at baseline from UK Biobank were included with measurements of serum IGF-1 at baseline. Main outcomes were incidence of CVD, including CVD mortality, coronary heart disease (CHD), myocardial infarction (MI), heart failure (HF), and stroke.

Results

Over a median 11.6 years of follow-up, UK Biobank documented 35 803 incident CVD cases, including 4231 from CVD-related death, 27 051 from CHD, 10 014 from MI, 7661 from HF, and 6802 from stroke. Dose-response analysis showed a U-shaped relationship between IGF-1 levels and cardiovascular events. Compared with the third quintile of IGF-1, the lowest category of IGF-1 was associated with increased risk of CVD (hazard ratio 1.128; 95% CI, 1.093 to 1.164), CVD mortality (1.294; 1.181 to 1.418), CHD (1.118; 1.078 to 1.159), MI (1.071; 1.008 to 1.139), HF (1.185; 1.107 to 1.268), and stroke (1.149, 1.070 to 1.235); also, the highest category was associated with increased risk of CVD (1.056; 1.020 to 1.094), CVD mortality (1.111; 1.000 to 1.236), CHD (1.070; 1.028 to 1.114), MI (1.111; 1.041 to 1.187) and HF (1.098; 1.015 to 1.188) after multivariable adjustment.

Conclusion

This study indicates that both low and high levels of circulating IGF-1 are associated with increased risk of CVD in general population. These results highlight the importance of monitoring IGF-1 status on cardiovascular health.
British Planters and the Origins of Wildlife Conservation in Colonial Sri Lanka
Authors: Guneratne Arjun
Published: February 2023

This article argues that the interests of coffee and tea planters in colonial Sri Lanka shaped the foundations of wildlife conservation policies, in which the state only played a secondary role. By destroying the forests of the highlands, they were the principal architects of ecological change on the island in the nineteenth century. Their principal mode of recreation, hunting, also shaped their engagement with natural history. Some were naturalists in their own right; others funneled specimens and observational data to other students of natural history. They lobbied for the first game laws, not through remorse for their own role in the destruction of wildlife (the “penitent butchers” thesis) but to keep the peasantry from competing for the species that they sought, which had been decimated by the actions of both groups. The way planters engaged with nature, through hunting and the pursuit of natural history, motivated them to preserve what was left of the island's wild fauna.
Technique for Validation of Intraoperative Navigation in Minimally Invasive Spine Surgery
Authors: Rudy Robert F. , Farber S. Harrison , Godzik Jakub , Dugan Robert K. , Gandhi Shashank V. , Turner Jay D. , Uribe Juan S.
Published: February 2023

BACKGROUND:

Intraoperative 3-dimensional navigation is an enabling technology that has quickly become a commonplace in minimally invasive spine surgery (MISS). It provides a useful adjunct for percutaneous pedicle screw fixation. Although navigation is associated with many benefits, including improvement in overall screw accuracy, navigation errors can lead to misplaced instrumentation and potential complications or revision surgery. It is difficult to confirm navigation accuracy without a distant reference point.

OBJECTIVE:

To describe a simple technique for validating navigation accuracy in the operating room during MISS.

METHODS:

The operating room is set up in a standard fashion for MISS with intraoperative cross-sectional imaging available. A 16-gauge needle is placed within the bone of the spinous process before intraoperative cross-sectional imaging. The entry level is chosen such that the space between the reference array and the needle encompasses the surgical construct. Before placing each pedicle screw, accuracy is verified by placing the navigation probe over the needle.

RESULTS:

This technique has identified navigation inaccuracy and led to repeat cross-sectional imaging. No screws have been misplaced in the senior author's cases since adopting this technique, and there have been no complications attributable to the technique.

CONCLUSION:

Navigation inaccuracy is an inherent risk in MISS, but the described technique may mitigate this risk by providing a stable reference point.
An Intelligent Arabic Model for Recruitment Fraud Detection Using Machine Learning
Authors: Sofy Mohamed A. , Khafagy Mohammed H. , Badry Rasha M.
Published: February 2023

Over the last years, with the tremendous growth of digital transformation and the constant need for companies to hire employees, huge amounts of fraudulent jobs have been posted on the internet. A cleverly planned sort of scam aimed at job searchers for a variety of unprofessional purposes is a false job posting. It can lead to a loss of money and effort. An Arabic intelligent model has been built to avoid fraudulent jobs on the Internet using machine learning, data mining, and classification techniques. The proposed model is applied to the Arabic version of the EMSCAD dataset. It is available on the Internet in the English version and it has been retrieved from the use of a real-life system and consists of several features such as company profile, company logo, interview questions, and more features depending on job offer ads, Firstly, EMSCAD is translated into the Arabic language. Then, a set of different classifiers such as Support Vector Machine (SVM), Random Forest (RF), Naïve Bayes (NB), and K-Nearest Neighbor (KNN) was used to detect the fraudulent jobs. Finally, the results were compared to determine the best classifier used for detecting fraudulent jobs. The proposed model achieved better results when using a Random Forest classifier with 97% accuracy.
A Modified Selective Mapping Technique for Peak-to-Average Power Ratio Reduction in Orthogonal Frequency Division Multiplexing with Index Modulation Systems
Authors:   Dept. of Information and Communication Engineering, Chaoyang University of Technology, Taichung, Taiwan, Liu Hsiu-Wen , Liang Hsin-Ying
Published: February 2023

In this study, we propose a modified selective mapping (SLM) technique to reduce the Peak-to-Average Power Ratio (PAPR) of Orthogonal Frequency Division Multiplexing with Index Modulation (OFDM-IM) systems. The main reason for using Reed–Muller and Polar codes is to protect the information bits to be transmitted while providing error correction capability and improved PAPR performance to the transmitted signal. Although OFDM-IM technology is a popular communication transmission technology recently, one of its disadvantages is that the transmitted signal has a high PAPR. The proposed method uses the Hamming weight distribution of the specific order Reed–Muller code to create a corresponding lookup table to select the subcarriers that are active in the OFDM-IM system. Moreover, it can correct errors in the information used. The proposed method also uses Polar codes as a channel encoder of the OFDM-IM system to analyze its performance in improving the PAPR. The simulation results show that method can not only improve the PAPR performance of OFDM-IM systems but also provide OFDM-IM transmission-signal error correction capacity.
Fewer Clicks, More Purchases
Authors: Unal Murat , Park Young-Hoon
Published: February 2023

E-commerce retailers are increasingly faced with challenges of finding ways to provide a seamless shopping experience to customers. The checkout process and its related touch points are especially critical in shaping the customer experience. We study the impact of adopting one-click buying, a feature that reduces the number of steps required to place a purchase order to a single click, on subsequent customer behavior. Using quasi-experimental data over a period of 35 months from an online retailer before and after the launch of one-click buying, we find adopting one-click buying is effective in lifting customer purchases and does so by making treated customers purchase more often and more items. The impact of adopting one-click buying on customer purchases after adoption is economically significant, persistent over time, and heterogeneous across customers. Analyzing clickstream data of customer activity online and purchases across product categories, we provide evidence that the increase in purchases is driven by richer engagement through both more visits to the website and more page views on visit and the expansion of purchases across categories. We discuss the implications of our findings for customer experience and targeting.

This paper was accepted by Duncan Simester, marketing.

Supplemental Material: The data files are available at https://doi.org/10.1287/mnsc.2023.4716 .
A scoping review of burn care in Southeast Asia
Authors: Handayani Estrin , Wahyuningtyas Eka Sakti , Nugroho Hananto Ponco
Published: February 2023

Background:

Non-fatal burns are a major cause of morbidity, with incidents often occuring at home and at work. Almost all burn cases occur in the WHO region, precisely in African and Southeast Asian countries. Yet, the epidemiology of these injuries, especially in the WHO-defined Southeast Asian Region, has yet to be adequately defined.

Method:

A scoping review of the literature was performed to identify epidemiology of thermal, chemical, and electrical burns in the WHO-defined Southeast Asian Region. The database search screened 1023 articles in total, of which 83 articles were assessed for eligibility at a full-text level, and 58 of these were excluded. Therefore, 25 full-text articles were included for data extraction and analysis.

Results:

Data analysed included demographics, injury details, burn mechanism, total body surface area burned, and in-hospital mortality.

Conclusion:

Despite the steady increase on burns research, the Southeast Asian region is still limited in terms of burns data. This scoping review has shown that the largest set of articles on burns come from Southeast Asia, indicating the importance of reviewing data at a regional or local level, as global studies tend to be dominated by data from high-income countries.
Consumo y Producción Responsable en el Antropoceno: Ética Animal y los Objetivos de Desarrollo Sostenible
Authors: Fernández-Mateo Joaquín , Franco-Barrera Alberto
Published: February 2023

Los Objetivos de Desarrollo Sostenible (ODS) son un llamado a la acción para los gobiernos, organizaciones y sociedad civil; un llamamiento para abordar los problemas ambientales y sociales del siglo XXI. Sin embargo, la Agenda 2030 no se centra en la ética animal como una de las claves para tratar estos temas tan críticos. Los diferentes enfoques éticos sobre el estatus moral de los animales no-humanos justifican la transición hacia dietas basadas en alimentos vegetales, no solo por las consecuencias ecológicas y geológicas del consumo de productos animales, sino también en concordancia con los principios de justicia. Este trabajo pretende destacar las consecuencias del consumo de productos animales en el Antropoceno. El ser humano se ha convertido en una fuerza geológica: El Antropoceno es la nueva época geológica desencadenada por la actividad humana que reemplaza al Holoceno. Sus efectos tienen un gran impacto sobre la biodiversidad, la deforestación, los recursos hídricos, el clima y la salud. Las siguientes líneas exploran la necesidad de desarrollar un criterio normativo para el uso de la tecnología para proteger el estado moral de los animales no-humanos: la innovación tecnológica debe centrarse en el desarrollo de alternativas para los alimentos de origen animal.
El acto de telemedicina: hacia un nuevo concepto de asistencia médico-personal
Authors: Camacho Clavijo Sandra
Published: February 2023

Gracias a la equivalencia funcional entre acto médico y acto de telemedicina, la prestación sanitaria a distancia queda sujeta a las exigencias deontológicas, legales y profesionales previstas para toda actuación médica. Sin embargo, la calificación jurídica del acto de telemedicina como acto médico suscita el debate sobre si la prestación médica a distancia cumple con la exigencia de prestación personal y directa del acto médico. Este estudio, analiza esta cuestión y su resolución en diferentes sistemas jurídicos, como el francés, el español, el alemán y el austriaco. De este análisis comparativo, resultarán los elementos necesarios para reflexionar sobre la nueva configuración de la relación asistencial personal como presupuesto de la regulación del acto de telemedicina.
Automated segmentation and quantification of calcified drusen in 3D swept source OCT imaging
Authors: Lu Jie , Cheng Yuxuan , Li Jianqing , Liu Ziyu , Shen Mengxi , Zhang Qinqin , Liu Jeremy , Herrera Gissel , Hiya Farhan E. , Morin Rosalyn , Joseph Joan , Gregori Giovanni , Rosenfeld Philip J. , Wang Ruikang K.
Published: February 2023

Qualitative and quantitative assessments of calcified drusen are clinically important for determining the risk of disease progression in age-related macular degeneration (AMD). This paper reports the development of an automated algorithm to segment and quantify calcified drusen on swept-source optical coherence tomography (SS-OCT) images. The algorithm leverages the higher scattering property of calcified drusen compared with soft drusen. Calcified drusen have a higher optical attenuation coefficient (OAC), which results in a choroidal hypotransmission defect (hypoTD) below the calcified drusen. We show that it is possible to automatically segment calcified drusen from 3D SS-OCT scans by combining the OAC within drusen and the hypoTDs under drusen. We also propose a correction method for the segmentation of the retina pigment epithelium (RPE) overlying calcified drusen by automatically correcting the RPE by an amount of the OAC peak width along each A-line, leading to more accurate segmentation and quantification of drusen in general, and the calcified drusen in particular. A total of 29 eyes with nonexudative AMD and calcified drusen imaged with SS-OCT using the 6 × 6 mm2 scanning pattern were used in this study to test the performance of the proposed automated method. We demonstrated that the method achieved good agreement with the human expert graders in identifying the area of calcified drusen (Dice similarity coefficient: 68.27 ± 11.09%, correlation coefficient of the area measurements: r = 0.9422, the mean bias of the area measurements = 0.04781 mm2).
Characterization of the photoelastic dispersion coefficient using polarized digital holography
Authors: Leal da Silva Sidney , Prado Felipe Maia , Toffoli Daniel José , Wetter Niklaus Ursus
Published: February 2023

The photoelastic dispersion coefficient represents the relationship between stress and the differences in refractive indices in a birefringent material. However, determining the coefficient using photoelasticity is challenging, as it is difficult to determine the refractive indices within photoelastic samples that are under tension. Here we present, for the first time, to our knowledge, the use of polarized digital holography to investigate the wavelength dependence of the dispersion coefficient in a photoelastic material. A digital method is proposed to analyze and correlate the differences in mean external stress with differences in mean phase. The results confirm the wavelength dependence of the dispersion coefficient, with an accuracy improvement of 25% compared to other photoelasticity methods.
Using rules of thumb in the design of physical optics systems
Authors: Lawrence George N.
Published: February 2023

Design is primarily a creative process. Theory provides us the knowledge we need and numerical modeling allows us to visualize a system and to optimize construction parameters, but neither is sufficient to perform design except in the simplest cases where a solution may be derived.
Holographic Optical Module Integrated with Chip Elements for Optical Disk Pickups
Authors: Ono Yuzo
Published: February 2023

Optical disk memories, especially CD-ROMs, have begun to be equipped commonly in desktop personal computers as a key device for mass memories in the recent multimedia circumstances. A demand for equipping them into notebook PCs will be a matter before long. To use in notebook PCs by reducing their optical pickup thickness, the authors have already developed an optical pickup integrated with bear laser diode and photodiode chips and a holographic optical elemento.
User Application Requirements for Optical Storage
Authors: Ryland Jane N.
Published: February 2023

The ability to store data using optical technology offers tremendous potential for increasing storage density and capacity while significantly reducing the cost of storage. However, the special characteristics of optical technology suggest that is is most appropriate for a particular set of applications rather than for indiscriminately replacing conventional magnetic tape or disk. In light of this, it is appropriate to assess those applications which appear to be well suited for optical storage from the standpoint of requirements which they impose on the architecture of an optical storage product. The assessment in this paper addresses a set of generic applications and then derives a general set of optical storage requirements from these applications.
The Stability of Te and Te-Alloy Films for Optical Data Storage
Authors: Lee Wen-yaung , Wieder H.
Published: February 2023

Thin Te films(5-30nm) are the most widely studied media for optical data storage due to their excellent laser writing characteristics. However, the archival life time of Te films still remains an important issue. We reported1 previously that the degradation resistance of thin Te films can be significantly improved by adjusting the deposition conditions and by a post thermal annealing step. Since information is stored in ~1μm size holes in optical recording, degradation studies based on measurements over a large area(e.g., 1cm2) can not be expected to provide complete archival life time data if degradation occurs within 1μm2 area. To this end, degradation studies have to be carried out microscopically. We have been studying both the macro- and micro-corrosion of Te and Te-alloy films. Some results of these studies are reported here.
Laser Diode Read/Write Characteristics of 3M’s Optical Storage Media
Authors: Freese Robert P.
Published: February 2023

Summary not available.
Automatic Loop gain Control System of DAD Player’s tracking servo
Authors: Iso Yoshimi , Nakagaki Harushige , Nakamura Masafumi , Inoue Shigeki
Published: February 2023

The Digital Audio Disc and Player will be put on the market in '82 Autumn, for expectation consumer products. In 3 spots pick up System, which is composed of main-spot for reading recorded signal and focusing servo, and of 2 side-spots for getting track following signal, lens actuator noise appears in playback. For audio products, the noise is fatal defect. So, it is important, to decrease the noise. The detector sensitivity of track following signal level is deviated by the disc characteristics of reflection ratio, modulation, and crosstalk etc. However, DAD Player needs the stable pick up servo system for any disc. We developed the Automatic Loop gain Control System which solved those problems.
An Interactive Multiple Servo System for an Optical/Digital Drive
Authors: Getreuer K. W. , Berg T. E. , Hulshof J. J. M.
Published: February 2023

Analysis showed that the servo system should have less than 0.4 um dynamic focus error. This accuracy could be guaranteed with a standard high bandwidth second order loop with lead lag compensation and a low frequency integrator. In the electronic design attention has been paid to avoid signal saturation during seeks due to optical crosstalk between the focus and the tracking channel. This crosstalk is discussed in a companion paper.(2) A measurement of the focus loop transfer function can be found in figure 1.
High Data Rate Erasable Magneto-Optic Media Tester
Authors: Kowalski Dan C. , Chen Tu , DePuy Charles W. , Treves David , Sitts Gary , Klinger Lance , Curry Donald J. , Sprague Robert A.
Published: February 2023

A portable highly stable air bearing magneto-optic tester is described that has been used to evaluate first and second surface media. The system was designed to handle 14 and 12 inch diameter disks with inner diameter holes similar to magnetic disks. Disk substrates made of glass, plastic, or aluminum can be tested at spin rates in the range of 200 to 3600 RPM. Two electromagnets are built into the tester. One is used to saturate the media and another to supply the write and erase field. A single optical head is used to write and read out data. The disk drive system is built of heavy aluminum plates in the form of a compact cage. An air bearing spindle driven by a brushless dc motor is used to spin the disk. The disk runs over the optics module in an inverted configuration selected to minimize the problem of dust settling on first surface media and to provide the means of working with smaller diameter disks. An air bearing slide is used to move the optical head. This slide is driven by a Compumotor stepper motor through a precision V-nut and screw. The stepper motor and controller combination can achieve a resolution of 1/20 micrometer per step. The stability of the media tester with glass disks is such that it can sit on a written one micrometer wide track for onver 30 minutes without noticing any degrading effect on the output signal.
Storage Technology Corporation Optical Storage Error Control*
Authors: Perera S. Robert , O'Keeffe Mike
Published: February 2023

Data storage devices used in computer systems are intolerant of even very low error rates. A single error can destroy valuable user data, or, even worse, generate inaccurate results. Since optical media, used in optical storage devices, cannot be pretested, or certified, as can magnetic media, a considerable technological challenge existed in designing an error control system for the Storage Technology 7640 Optical Storage Unit. The design objective was to make the 7640 as reliable as current state-of-the-art magnetic storage devices, while using minimum overhead, and operating at system level throughput rates of 3 MBytes/sec.
A Measured Optical Disk Media Error Model and a Compatible Error Management Implementation
Authors: Hoover J. H. , Waring J. L.
Published: February 2023

The bit-error-rate (BER) performance of well designed Optical Disk Recording Systems, like their magnetic recorder predecessors, depends on how well the media error model is known and how compatibly the recorder error management system is designed. The use of diffraction limited, argon laser spots to write and read has led to implementations with high linear packing densities (80 KBPI) and very high track pitches (1.0 um). With this high areal packing density, small defects mask many bits over a number of tracks. An additional complexity is that media tuned for use at the argon wavelengths is not yet commercially available. These factors force the system designer to implement a flexible error management system which can be tailored to the media defect distribution as the media evolves.
Optical Disk Testing Methods Summary
Authors: LaBudde Edward V. , Hazel Robert
Published: February 2023

The purpose of this presentation is to explore the test requirements for optical disk media in a production environment. The basic purposes for production testing of media include: process control, media certification and maintenance of quality control standards. Each of these purposes has special test requirements and considerations on the types and methods for data collection and display.
A Thermosetting Resin Substrate for Computer-Use Optical Memory Disks
Authors: Ohsawa S. , Tusge M. , Takatsu A. , Okunishi T. , Tanaka J. , Mikami S.
Published: February 2023

A thermosetting resin (epoxy resin) substrate for computer-use write-once, phase-change and magneto-optical memory disks has been developed and its optical, physical, thermal and mechanical properties are described in comparison with other plastic substrates.
Thermal Analysis of Thin Films Under Pulsed Laser Irradiation
Authors: Shin Sung-Chul
Published: February 2023

A two-dimensional finite-difference method was developed to study the thermal behavior of thin films, irradiated by a pulsed Gaussian laser beam. In particular, the method was applied to rare earth-transition metal alloy films for magnetooptical recording. The effects of the film parameters (thermal conductivity, specific heat, absorption coefficient and film thickness) and the laser parameters (output power, pulse width and beam size) on the heating and cooling behavior were extensively investigated. It was found that the temperature profile of a film was sensitively dependent on those parameters. The results might be utilized to predict the recorded bit size and also to optimize the laser parameters. For a given energy density of a laser beam, a large output power with a short pulse width was desirable for effective heating of a film. It was also found that heating by radial thermal diffusion became important with increasing thermal conductivity of a film. Therefore, to achieve high storage density, a film is required to have low thermal conductivity.
Measuring Two Dimensional OTF Applying CT Principle
Authors: Xiang-yang Yang , Min-shian Wu , Kuo-fan Chin
Published: February 2023

In optical disc system, the precise measurement and evaluation of focused micro-laser-spot (usually less than lum in diameter) is very important. To meet this requirement, a new method using the concept of CT scanner has been developed. A knife-edge scans the spot on the image plane. Differentiating the signal received by the detecter under the knife-edge, we get a one-dimension (1-D) projection of 2-D laser spot. Rotating the knife-edge slightly, we can get different projections at different angles. The projections measured are processed by taking the convolution and back-projecttion, just done as in the CT scanner. In this way, we get the 2-D profiles of the spot, i.e. the Point Spread Function (PSF) of the optical head. The shape and size of the spot can be got directly from the profile. The 2-D Fourier Transform of PSF results in the OTF of the optical head, which discribes the quality of the optical system quantitatively.
Erasable Digital Audio Disc System
Authors: Torazawa Kenji , Minechika Shigekazu , Murata Seiji , Ishii Yasuhiro
Published: February 2023

Following up the popularization of Compact Disc (CD), the epoch of digtial audio is coming really and truly. In the new period the actualization of an erasable optical disc system will be expected greatly.
A 5 1/4″ Optical Digital Data Storage Drive
Authors: Chen Di , Yew Nelson
Published: February 2023

A number of Optical Digital data storage devices were introduced in recent years. Most of these devices use a 12" diameter write-once-read-mostly (WORM) optical disk with a capacity around 1 GByte per disk side. These devices are aimed at the high end of data storage hierarchy, and larger capacity is also necessary to bring the cost per bit to a reasonable value when the cost of laser and optics are high at the early stage of development. Much progress has been made in the past two years. The success of laser diode based compact audio disk players in the market place has changed this situation dramatically. It is now economically feasible to produce optical digital recording devices with a formfactor of a 5 1/4" Winchester drive, using a 130 mm diameter WORM disk, to store 200 MByte/side, and compete favorably with existing magnetic recording devices on a cost per bit basis.
Amorphous Carbon Dielectric Coatings for Magneto-Optic Recording Media
Authors: Robinson C. J. , Payne R. N. , Bell A. E.
Published: February 2023

Dielectric coatings play an important role in the overall design of active layers for magneto-optic recording. When coated to the thickness required to establish an antireflection condition, an enhancement of the shot noise limited carrier to noise ratio is possible, and significant reduction in the rate of oxidation of the Rare Earth/ Transition Metal (RE-TM) layer is achieved by sandwiching this layer between adjacent layers of certain dielectrics. Even though many dielectrics offer excellent properties in terms of low permeability to oxygen and water vapor, in some cases (for example SiO2) degradation of the RE-TM layer can still proceed via oxidation of the rare earth element, occurring at the RE-TM/dielectric interface(1). In this respect, amorphous C:H coatings would seem to have an advantage advantage, and in this paper we describe a study of the optical properties, surface passivation characteristics and effect on dynamic disk recording performance of amorphous C:H films deposited into active layer structures with TbFe and TbFeCo alloys. The amorphous C:H films were produced by RF plasma deposition from CH4 in a conventional diode reaction chamber. Relatively high deposition rates of 90Å/min are readily achieved. The physical structure and properties of a-C:H films are widely reported, but in particular they are known for their high hardness, low electrical conductivity (σ=10-9 ohm-1 cm-1), high refractive index (n=2.1) and are often termed "diamond like carbon" in the literature. Such films are also optically transparent in the IR, chemically stable, inert, homogeneous (i.e. low pin hole density) and have found wide application elsewhere in the field of optical coatings in the IR.
Photo Polarization and Depolarization Studies in Photorefractive Bismuth Silicon Oxide Crystal
Authors: Pillai P. K. C.
Published: February 2023

Photopolarization, dark and photo-depolarization studies hcve been carried out in detail in the photorefractive Bismuth Silicon Oxide Single Crystal (BSO). The polarization state in the crystal has been induced by the simultaneous application of a DC field and an illumination for a known time. The depolarization current decay characteristics of the polarized crystal have been studied under dark and under re-illumination of the sample. The crystal has been polarized by varying the polarizing field, illumination and time. It has been found that remanent polarization presist in the crystal for a long time after the removal of the poling field and illumination. The persistance of polarization, its magnitude and also the decay mode are very much dependent on the poling conditions. The total charge obtained under different conditions of polarization has been calculated and found to be dependent on poling parameters. These results show that prepolarized BSO crystals can be usefully employed in volume holographic recording, optical memory and electrophotographic image storage.
Accelerated Aging Studies for Organic Optical Data Storage Media.
Authors: Nikles David E. , Forbes Charles E. , Goldberg Harris A. , Johnson Robert E. , Kohn Rachel S. , Onorato Frank J.
Published: February 2023

This paper reports the results of some accelerated aging studies for HCC organic WORM media. The goal of these studies was to obtain aging data for disks exposed to high tempera­ture and high humidity. The data allowed a direct comparison with the results for other commercial media.
An Introduction to the Insite 325 Floptical Disk Drive
Authors: Godwin Jim
Published: February 2023

Disk drives using optical memory technology are being introduced to the market featuring high capacity, removable media. The improved capacity is available at a significant cost premium over magnetic memory devices for the drive as well as the media. While the linear bit density of present magnetic disk drives matches that of optical disk drives (see Table 1), new advancements in Barium-Ferrite (BaFe) magnetic media will soon allow magnetic bit densities to increase, exceeding optical bit densities by a factor of two or more. By contrast, track densities of removable magnetic media are 15 to 100 times less than their optical counterparts. Increasing track density to over 1000 tracks per inch on a removable, inexpensive, flexible magnetic medium has only recently been achieved by Insite Peripherals.
Optical Storage System Architecture
Authors: Bessette O. E.
Published: February 2023

10 GByte erasable disks, 150 Mb/s heads and four controller modules are configurable for spaceflight and ground storage systems to terabyte capacity and Gb/s data rates.
Holographic Servo-signal Detection Stabilized to the Wavelength Fluctuation and the Mechanical Misalignment in the Optical Heads
Authors: Kato Makoto , Saimi Tetsuo , Kadowaki Shin-ichi , Komma Yoshiaki
Published: February 2023

Among recent studies on holographic optical elements(HOEs) are those to develop compact substitutes for the beamsplitting prism and lens systems in the optical heads. The holographic heads1-4 presented so far, however, have been based on the conventional servo-detection methods that required precise beam-positioning at the photodetectors. Thus HOEs, applied to both the astigmatic optics2,3 and the double knife-edge method,1,3,4 suffered some serious drawback due to the wavelength shift of the diode laser source, typically Δλ ≳ 5nm.1,2
Scanning Optical Microscopy: A Powerful Tool for Studying the Physical and Optical Processes in Optical Recording.
Authors: Coombs J.H. , Holtslag A.H.M.
Published: February 2023

A Scanning Optical Microscope (SOM) detects variations in the optical reflection of a focussed laser beam from a surface, and therefore the information it gives is directly comparable to the response of an optical disc player/recorder. However, being a microscope, it is not limited to signals along a single line across a surface (as in a recorder), but can provide 2-Dimensional images of local regions of the surface under a variety of optical detection schemes, resolutions and aberrations. It can thereby not only model the optical recorder response, but provide quantitative information on the physical origin of the contrast observed. In this summary we will briefly outline the possible uses of the SOM as a tool in Optical Recording, and provide a few examples of its application.
Margin Measurements of Pulse Amplitude Modulation Channels
Authors: Lauffenburger Jim , Arachtingi John , Robbins Jamey , Kim Jong
Published: February 2023

High capacity optical disk drives are in production which conform to the ANSI proposal BSR X 3.191, known as the 130mm Write-Once Sampled Servo RZ Selectable Pitch Optical Disk Cartridge (reference 1). The capacity of these cartridges is 1280 million bytes available to the user, under ECC protection.
The Use of FEM Modes in Time Domain Servo Simulations
Authors: Ernst Charles H.
Published: February 2023

In the analysis of disk drive actuator performance, several techniques are used, including finite element analysis, frequency domain analysis, and time domain analysis. The finite element analysis is used to obtain the natural modes and frequencies of the actuators, baseplate, spindle, and other mechanical components. These results are primarily used to understand the resonant frequencies of the components and the system as a whole, with an eye toward designing servo systems which do not interact with these structural modes in a deleterious way. The servo electronics are usually analyzed separately in either a frequency domain or a time domain analysis, and the structural effects of the actuators and other mechanical components are either ignored or simply modeled as a one or two degree of freedom lumped mass.
Erasable Compact Disc Using Phase Change Optical Media
Authors: Ohno Eiji , Nishiuchi Kenichi , Yamada Noboru , Akahira Nobuo
Published: February 2023

An application of phase change optical media for a erasable compact disc(CD) has been studied. As the phase change optical disks have featuring properties; overwritable only by power modulation of a single laser beam and detectable reproducing signals directly by reflectivity changes, it can be said that they intrinsically have high compatibility with commercial read-only CD or write-once CD. Recording the CD format signals means pulse width modulation (PWM) recording at low linear velocity. Accordingly, teardrop shaped distortions of recording marks, which are common problems for heat-mode recording media, should be suppressed.
Multifunction Grating for Signal Detection of Optical Disk
Authors: Gupta Mool C. , Peng S. T.
Published: February 2023

Light diffraction by periodic structures finds applications in various areas such as integrated optics, holography, acousto-optics, optical data storage, and data processing etc. Here we discuss the light diffraction by periodic structures for optical storage applications. In this paper we present theoretical and experimental results of polarization separation characteristics of surface relief diffraction gratings and its use in signal detection from optical disk.
Costar: A Focus Sensing Method with Improved Pattern Noise Rejection.
Authors: Marshall D. R.
Published: February 2023

Most focus sensing schemes rely on an array of optical detector elements placed in a beam of light reflected from the recording medium so that redistribution of optical power on the detector elements should sensitively and accurately indicate the state of focus of the spot. However, small changes in the spatial distribution of optical power on these detectors, caused for example by beam motion, diffraction, or partial obscuration, may cause relatively large inaccuracies in the focus error signal. I will refer to these effects collectively as "pattern noise", by which I mean all spurious local redistributions in optical power in a light beam used to generate optical error signals.
An overview on CD Technologies
Authors: Ogawa Hiroshi
Published: February 2023

It has been about 12 years passed since the first audio CD player was released. During these 12 years, various technologies have been developed and many standards have been established in the period of the Red Book for CDDA and the Orange Book part II for CD-R.
6 Channel Dolby Stereo Digital Sound Mastering And Transfer Using Mo Disks
Authors: Goldberg Paul R.
Published: February 2023

The Dolby Stereo Digital film sound system is Dolby’s next logical development beyond the Dolby Stereo A-type and SR-type systems. SR*D, the name of the print format used by the Dolby Stereo Digital system, is derived from SR (Dolby’s Spectral Recording) and D (for Digital), since both signals coexist on the film print. The system is officially known as Dolby Stereo Digital in theatres, and will be known as Dolby Surround Digital in the home theatre market.