bluuebunny/crossref_metadata_2025 huggingface dataset:
Stimulation of the Presupplementary Motor Area Cluster of the Subthalamic Nucleus Predicts More Consistent Clinical Outcomes
Authors: Kähkölä Johannes , Lahtinen Maija , Keinänen Tuija , Katisko Jani
Published: January 2023

BACKGROUND:

The development of diffusion tensor imaging and tractography has raised increasing interest in the functional targeting of deep brain stimulation of the subthalamic nucleus (STN) in Parkinson disease.

OBJECTIVE:

To study, using deterministic tractography, the functional subdivisions of the STN and hyperdirect white matter connections located between the STN and the medial frontal cortex, especially the presupplementary motor area (preSMA), SMA, primary motor area (M1), and dorsolateral premotor cortex, and to study retrospectively whether this information correlates with clinical outcome.

METHODS:

Twenty-two patients with Parkinson disease who underwent STN deep brain stimulation were analyzed. Using 3 T MR images, the medial frontal cortex was manually segmented into preSMA, SMA, M1, and dorsolateral premotor cortex, which were then used to determine the functional subdivisions of the lateral border of the STN. The intersectional quantities of the volume of activated tissue (VAT) and the hyperdirect white matter connections were calculated. The results were combined with clinical data including unilateral 12-month postoperative motor outcome and levodopa equivalent daily dose.

RESULTS:

Stimulated clusters of the STN were connected mostly to the cortical SMA and preSMA regions. Patients with primarily preSMA cluster stimulation (presmaVAT% ≥ 50%) had good responses to the treatment with unilateral motor improvement over 40% and levodopa equivalent daily dose reduction over 60%. Larger VAT was not found to correlate with better patient outcomes.

CONCLUSION:

Our study is the first to suggest that stimulating, predominantly, the STN cluster where preSMA hyperdirect pathways are located, could be predictive of more consistent treatment results.
Surgical Management in Herpes Simplex Encephalitis: Illustrative Case Report and Systematic Review of the Literature
Authors: Bhave Varun M. , Bernstock Joshua D. , Carlson Julia M. , Kappel Ari D. , Torio Erickson F. , Chen Jason A. , Essayed Walid Ibn , Gawelek Kara L. , DiToro Daniel F. , Izzy Saef , Cosgrove G. Rees
Published: January 2023

BACKGROUND:

Herpes simplex virus (HSV) is a common cause of viral encephalitis and can result in refractory seizures. Although HSV encephalitis (HSVE) is treated primarily with acyclovir, surgery can play a role in medically intractable cases.

OBJECTIVE:

To systematically review cases describing surgery for the treatment of severe HSVE. We also present an illustrative case of anterior temporal lobectomy (ATL) for refractory status epilepticus in a patient with unilateral HSVE. This case demonstrates one clinical context in which surgery can be a useful adjunct.

METHODS:

We performed a systematic review using PubMed and Google Scholar, including case reports and series describing surgical interventions for HSVE. Clinical data were extracted from 54 publications that incorporated 67 patient cases.

RESULTS:

Surgical decompression occurred at a wide range of times after the onset of illness, although most patients were operated on 4 or more days after HSVE symptoms began. Numerous reports indicated that decompressive craniectomy, temporal lobectomy, and hematoma removal could treat intractably elevated intracranial pressure because of HSVE with favorable long-term outcomes. We describe an additional case in which a 52-year-old woman with HSVE developed refractory right temporal lobe seizures. After ATL, the seizures resolved with significant clinical improvement.

CONCLUSION:

Surgical treatment can be a useful adjunct for treatment of HSVE. There is substantial variability in the timing of surgical decompression in patients with HSVE, which can be necessary up to approximately 3 weeks after illness onset. ATL should be considered for refractory status epilepticus in HSVE with a unilateral seizure focus.
Correlation of Pituitary Descent and Diabetes Insipidus After Transsphenoidal Pituitary Macroadenoma Resection
Authors: Ma Josh , Gooderham Peter , Akagami Ryojo , Makarenko Serge
Published: January 2023

BACKGROUND:

Endoscopic transsphenoidal surgery remains the technique of choice for resection of pituitary adenoma. Postoperative diabetes insipidus (DI) is most often transient and observed in 1.6% to 34% of patients, whereas permanent DI has been reported in 0% to 2.7% of patients. The proposed mechanism was the transduction of traction forces exerted by the surgeon on the descended diaphragma sellae and through the pituitary stalk.

OBJECTIVE:

To quantify and correlate the degree of pituitary gland descent with postoperative DI.

METHODS:

Of 374 patients who underwent transsphenoidal resection of a pituitary adenoma between 2010 and 2020 at our institution, we report a cohort of 30 patients (Group A) DI. We also report a matched cohort by tumor volume of 30 patients who did not develop DI (Group B). We quantified the tension on the pituitary stalk by calculating pituitary descent interval (PDI) by comparing preoperative and postoperative position of the pituitary gland and using Pythagoras' formula where

, with craniocaudal (CC) and anterior–posterior (AP) representing measurements of pituitary translation in respective directions after resection.

RESULTS:

Patients who developed DI had significantly greater pituitary gland translations in the craniocaudal (23.0 vs 16.3 mm, P = .0015) and anteroposterior (2.4 vs 1.5 mm, P = .0168) directions. Furthermore, Group A had a statistically greater PDI, which was associated with development of DI (23.2 vs 16.6 mm, P = .0017).

CONCLUSION:

We were able to quantify pituitary descent and subsequent tension on the pituitary stalk, while also associating it with development of postoperative DI after pituitary adenoma resection.
Anatomic Depth Estimation and Three-Dimensional Reconstruction of Microsurgical Anatomy Using Monoscopic High-Definition Photogrammetry and Machine Learning
Authors: Gonzalez-Romo Nicolas I. , Hanalioglu Sahin , Mignucci-Jiménez Giancarlo , Abramov Irakliy , Xu Yuan , Preul Mark C.
Published: January 2023

BACKGROUND:

Immersive anatomic environments offer an alternative when anatomic laboratory access is limited, but current three-dimensional (3D) renderings are not able to simulate the anatomic detail and surgical perspectives needed for microsurgical education.

OBJECTIVE:

To perform a proof-of-concept study of a novel photogrammetry 3D reconstruction technique, converting high-definition (monoscopic) microsurgical images into a navigable, interactive, immersive anatomy simulation.

METHODS:

Images were acquired from cadaveric dissections and from an open-access comprehensive online microsurgical anatomic image database. A pretrained neural network capable of depth estimation from a single image was used to create depth maps (pixelated images containing distance information that could be used for spatial reprojection and 3D rendering). Virtual reality (VR) experience was assessed using a VR headset, and augmented reality was assessed using a quick response code–based application and a tablet camera.

RESULTS:

Significant correlation was found between processed image depth estimations and neuronavigation-defined coordinates at different levels of magnification. Immersive anatomic models were created from dissection images captured in the authors' laboratory and from images retrieved from the Rhoton Collection. Interactive visualization and magnification allowed multiple perspectives for an enhanced experience in VR. The quick response code offered a convenient method for importing anatomic models into the real world for rehearsal and for comparing other anatomic preparations side by side.

CONCLUSION:

This proof-of-concept study validated the use of machine learning to render 3D reconstructions from 2-dimensional microsurgical images through depth estimation. This spatial information can be used to develop convenient, realistic, and immersive anatomy image models.
Flow Diversion as Destination Treatment of Intracranial Mycotic Aneurysms: A Retrospective Case Series
Authors: Kashkoush Ahmed , El-Abtah Mohamed E. , Achey Rebecca , Hussain Muhammad Shazam , Toth Gabor , Moore Nina Z. , Bain Mark
Published: January 2023

BACKGROUND:

Mycotic aneurysms represent a rare type of intracranial aneurysm. Treatment options usually consist of coiling, clipping, or liquid embolization. Data regarding outcomes after flow diversion of mycotic aneurysms are sparse.

OBJECTIVE:

To present a single-center case series regarding our experience with FD as definitive treatment for ruptured mycotic aneurysms initially treated with coil embolization.

METHODS:

We retrospectively reviewed a prospectively maintained database of all cerebrovascular procedures performed at a single institution between 2017 and 2021 for cases that used FD for the management of intracranial mycotic aneurysms. Prospectively collected data included patient demographics, medical history, rupture status, aneurysm morphology, aneurysm location, and periprocedural complications. The main outcomes included neurological examination and radiographic occlusion rate on cerebral digital subtraction angiography.

RESULTS:

Three patients with 4 ruptured mycotic aneurysms that were initially treated with coil embolization were identified that required retreatment. The aneurysms were located along the middle cerebral artery bifurcation (n = 2), posterior cerebral artery P1/2 junction (n = 1), and basilar artery apex (n = 1), which all demonstrated recurrence after initial coil embolization. Successful retreatment using flow diverting stents was performed in all 3 patients. At the last angiographic follow-up, all aneurysms demonstrated complete occlusion. No patients suffered new periprocedural complications or neurological deficits after FD.

CONCLUSION:

Flow-diverting stents may be an effective treatment option for intracranial mycotic aneurysms that are refractory to previous endovascular coiling. Future studies are warranted to establish the associated long-term safety and clinical efficacy.
Surgical Resection of Deep-Seated Arteriovenous Malformations Through Stereotactically Guided Tubular Retractor Systems: A Case Series
Authors: Achey Rebecca , Kashkoush Ahmed , Potter Tamia , Davison Mark , Moore Nina Z. , Kshettry Varun R. , Bain Mark
Published: January 2023

BACKGROUND:

Arteriovenous malformations (AVMs) in the subcortical and/or periventricular regions can cause significant intraventricular and intracranial hemorrhage. These AVMs can pose a unique surgical challenge because traditional, open approaches to the periventricular region require significant cortical/white matter retraction to establish sufficient operative corridors, which may result in risk of neurological injury. Minimally invasive tubular retractor systems represent a novel, feasible surgical option for treating deep-seated AVMs.

OBJECTIVE:

To explore 5 cases of NICO BrainPath-assisted resection of subcortical/periventricular AVMs.

METHODS:

Five patients from a single institution were operated on for deep-seated AVMs using tubular retractor systems. Collected data included demographics, AVM specifications, preoperative neurological status, postoperative neurological status, and postoperative/intraoperative angiogram results.

RESULTS:

Five patients, ranging from age 10 to 45 years, underwent mini-craniotomy for stereotactically guided tubular retractor-assisted AVM resection using neuronavigation for selecting a safe operative corridor. No preoperative embolization was necessary. Mean maximum AVM nidal diameter was 8.2 mm. All deep-seated AVMs were completely resected without complications. All AVMs demonstrated complete obliteration on intraoperative angiogram and on 6-month follow-up angiogram.

CONCLUSION:

Minimally invasive tubular retractors are safe and present a promising surgical option for well-selected deep-seated AVMs. Furthermore, study may elucidate whether tubular retractors improve outcomes after microsurgical AVM resection secondary to mitigation of iatrogenic retraction injury risk.
Above-The-Hairline Suboccipital Transverse Approach for the Treatment of Chiari I Malformation
Authors: Naylor Ryan M. , Rotter Juliana , Proctor Mark R. , Bite Uldis , Ahn Edward S.
Published: January 2023

BACKGROUND:

Chiari I malformation is a common pediatric neurosurgical disorder with an established treatment paradigm. Posterior fossa decompression and duraplasty (PFDD) is associated with symptom improvement but it carries postoperative risk, particularly cerebrospinal fluid (CSF) leak and wound complications. In addition, the cosmetic outcomes of PFDD have been overlooked in the literature.

OBJECTIVE:

To describe a novel approach for PFDD in which the transverse surgical incision is completely hidden above the hairline and to report early outcomes in a prospective patient cohort.

METHODS:

Clinical and cosmetic outcomes were recorded for 15 consecutive pediatric patients who underwent PFDD for Chiari I malformation via the above-the-hairline transverse suboccipital approach.

RESULTS:

The median clinical follow-up time was 6 months (range 1-12 months), and the majority of patients experienced significant improvement of their preoperative symptoms. Three patients (20%) experienced complications associated with surgery, which included injury to the greater occipital nerve, CSF hypotension and subfascial pseudomeningocele, and superficial wound dehiscence that resolved spontaneously with oral antibiotics. Zero patients (0%) returned to the operating room for persistent CSF leak, deep wound infection, or revision decompression. An excellent cosmetic outcome was achieved in 12 patients (80%). No patient had a poor cosmetic outcome.

CONCLUSION:

The above-the-hairline transverse suboccipital approach for PFDD in patients with Chiari I malformation offers favorable cosmetic outcomes and fascial closure while permitting adequate decompression.
Defining Occult High-Risk Cysts of the Pineal Region: A Case Series
Authors: Guadix Sergio W. , Marianayagam Neelan J. , Weidman Elizabeth K. , Yuan Melissa , Liechty Benjamin , Greenfield Jeffrey P. , Souweidane Mark M.
Published: January 2023

BACKGROUND:

Absence of hydrocephalus on neuroimaging may impart a false sense of security for patients with pineal cysts. In this case series, we characterize a subset of patients with pineal cysts having an occult presentation. Unifying features of worsening paroxysmal headaches suggesting intermittent obstructive hydrocephalus and radiographic evidence of third ventricular invagination characterize these patients as high risk.

OBJECTIVE:

To define features of occult, high-risk pineal cysts and outcomes of endoscopic cyst fenestration.

METHODS:

Charts were retrospectively reviewed for patients with pineal cysts evaluated at our institution between 2018 and 2021 who underwent endoscopic cyst fenestration. To capture cysts presenting as occult, patients were excluded if hydrocephalus was noted at presentation. Relevant clinical history, imaging, operative data, and clinical outcomes were reviewed.

RESULTS:

Of 50 pineal cyst patients, 4 satisfied inclusion criteria. All patients presented with worsening paroxysmal headaches. In addition, 75% (3/4) also experienced intermittent syncope. Patients exhibited no hydrocephalus (n = 3) or fluctuating ventricular size on longitudinal imaging (n = 1). In all cases, high-resolution sagittal 3-dimensional T2 magnetic resonance imaging demonstrated invagination of the cyst anteriorly into the posterior third ventricle. All patients underwent endoscopic cyst fenestration with complete symptom resolution (mean follow-up of 20.6 months; range 3.5-37.4 months).

CONCLUSION:

The clinical history for occult, high-risk pineal cysts is notable for worsening paroxysmal headaches and episodic alterations of consciousness suggesting intermittent obstructive hydrocephalus. Because ventricular size can appear normal on standard imaging protocols, clinical suspicion should trigger workup with high-resolution magnetic resonance imaging designed to detect these cysts. Endoscopic cyst fenestration is a safe and efficacious management strategy.
Optic cup morphogenesis across species and related inborn human eye defects
Authors: Cardozo Marcos J. , Sánchez-Bustamante Elena , Bovolenta Paola
Published: January 2023

The vertebrate eye is shaped as a cup, a conformation that optimizes vision and is acquired early in development through a process known as optic cup morphogenesis. Imaging living, transparent teleost embryos and mammalian stem cell-derived organoids has provided insights into the rearrangements that eye progenitors undergo to adopt such a shape. Molecular and pharmacological interference with these rearrangements has further identified the underlying molecular machineries and the physical forces involved in this morphogenetic process. In this Review, we summarize the resulting scenarios and proposed models that include common and species-specific events. We further discuss how these studies and those in environmentally adapted blind species may shed light on human inborn eye malformations that result from failures in optic cup morphogenesis, including microphthalmia, anophthalmia and coloboma.
Togetherness in the Household
Authors: Cosaert Sam , Theloudis Alexandros , Verheyden Bertrand
Published: January 2023

Spending time with a spouse is a major gain from marriage. We extend the classical collective model of the household to allow for togetherness between spouses. Togetherness takes the form of joint leisure and joint care for children. Using revealed preference conditions and Dutch data over the years 2009–2012, we find that households are willing to pay €1.20 per hour—10 percent of the average wage—to convert private leisure to joint leisure and €2.10 per hour to convert private childcare to joint childcare. Our results suggest togetherness is an important component of household time use despite being overlooked in the economics literature. (JEL D12, D13, J12, J13, J16, J22)
Dynamic Information Design under Constrained Communication Rules
Authors: Lorecchio Caio , Monte Daniel
Published: January 2023

An information designer wishes to persuade agents to invest in a project of unknown quality. To do so, she must induce investment and collect feedback from these investments. Motivated by data regulations and simplicity concerns, our designer faces communication constraints. These constraints hinder her without benefiting the agents: they impose an upper bound on the induced belief spread, limiting persuasion. Nevertheless, two-rating systems (direct recommendations) are the optimal design when experimentation is needed to generate information and  approximate the designer’s first-best payoff for specific feedback structures. When the designer has altruistic motives, constrained rules significantly decrease welfare. (JEL D64, D82, D83)
Contest Design with Stochastic Performance
Authors: Kirkegaard René
Published: January 2023

This paper studies optimal contest design in contests with noisy performance. Here, contest design is a team moral hazard problem that endogenizes the assignment rule that maps performance profiles into winning probabilities. The optimal design features endogenous standards for eligibility, and the number of prizes that are awarded may be stochastic. Generally, one group of agents is identified as “first claimants” of prizes, contingent on performance exceeding a threshold of excellence. However, which group wins prizes more often depends on the designer’s objective function and the performance technologies. Finally, the approach derives endogenous, microfounded, and fully optimal contest success functions. (JEL D44, D82)
Clinical value of combined preoperative–postoperative neutrophil-to-lymphocyte ratio in predicting hepatocellular carcinoma prognosis after radiofrequency ablation
Authors: Ni ZiHao , Wu BoLin , Liu Zhao , Wang QiuCheng , Han Xue , Cheng Wen , Guo CunLi
Published: January 2023

Objective:

Previous studies focused on the prognostic significance of the pre- or post-operative neutrophil–lymphocyte ratio (NLR); the significance of combined pre- and post-operative NLR (PP-NLR) remains unknown. Therefore, we investigated the value of PP-NLR for predicting prognosis after radiofrequency ablation (RFA) in patients with hepatocellular carcinoma (HCC) to improve treatment and prolong survival.

Methods:

We investigated pre- and post-operative NLR and PP-NLR in predicting prognosis after RFA in patients with HCC. Optimal thresholds for leukocytes, lymphocytes, neutrophils, and NLR before and after RFA were retrospectively assessed in patients with HCC who had undergone RFA between January 2018 and June 2019 in Harbin Medical University Cancer Hospital. Risk factors for early HCC recurrence and those affecting recurrence-free survival (RFS) were analyzed.

Results:

The respective pre- and post-operative optimal thresholds were as follows: neutrophils, 3.431 and 4.975; leukocytes, 5.575 and 6.61; lymphocytes, 1.455 and 1.025; and NLR, 1.53 and 4.36. Univariate analysis revealed tumor number; alpha-fetoprotein level; post-operative leukocytes, lymphocytes, NLR, and neutrophils; pre-operative neutrophils and NLR; and PP-NLR as factors influencing early recurrence and RFS. Multivariate analysis indicated PP-NLR as an independent risk factor for poor RFS and early recurrence.

Conclusion:

PP-NLR was more effective for predicting prognosis than pre- or post-operative NLR alone for patients with HCC.

Advances in knowledge:

The novelty of this study lies in the combination of pre- and post-operative NLR, namely PP-NLR, to study its prognostic value for HCC patients after RFA, which has not been found in previous studies. The contribution of our study is that PP-NLR can provide clinicians with a new reference index to judge the prognosis of patients and make timely treatment to help patients improve their prognosis.
Technical Note—Risk-Averse Regret Minimization in Multistage Stochastic Programs
Authors: Poursoltani Mehran , Delage Erick , Georghiou Angelos
Published: January 2023

Regret minimization has gained popularity in a wide range of decision-making problems under uncertainty because of its capacity to identify more opportunistic solutions than worst-case value optimization. Unfortunately, the rigidity of current worst-case regret models and scarcity of tractable solution methods have been serious obstacles in multistage applications. In “Risk-Averse Regret Minimization in Multistage Stochastic Programs,” M. Poursoltani, E. Delage, and A. Georghiou consider a multistage stochastic programming setting with a discrete scenario tree. They introduce the notion of the Δ-regret model, which bridges between the ex ante and ex post regret minimization paradigms that are currently used in the regret minimization literature for single-stage problems. The notion of Δ-regret minimization is investigated for the first time both theoretically and numerically in order to better understand its behavior under a set of popular risk measures.
Best of Both Worlds: Ex Ante and Ex Post Fairness in Resource Allocation
Authors: Aziz Haris , Freeman Rupert , Shah Nisarg , Vaish Rohit
Published: January 2023

Consider the problem of allocating indivisible goods among agents with additive valuations, where monetary payments are not allowed. When randomization is allowed, it is possible to achieve compelling notions of fairness such as EV, which states that no agent should prefer any other agent's allocation to their own. When allocations must be deterministic, achieving exact fairness is impossible but approximate notions such as EV up to one good can be guaranteed. In “Best of Both Worlds: Ex Ante and Ex Post Fairness in Resource Allocation,” H. Aziz, R. Freeman, N. Shah, and R. Vaish ask whether it is possible to achieve both types of guarantees simultaneously. More specifically, they ask whether there exists a probability distribution over deterministic allocations such that every deterministic allocation is envy-free up to one good and the distribution is exactly envy-free in expectation. The main result of the paper answers this question in the affirmative, showing that ex ante and ex post fairness need not be in conflict.
Dalbavancin for Successful Treatment of Infective Endocarditis Caused by Enterococcus faecalis
Authors: Teigell Muñoz Francisco Javier , Mateos-González María , Bernal-Hertfelder Elsa , Sánchez de Torre Ana , García-Ferrón María , de Cáceres Velasco Carmen , Bueno Muiño Coralia
Published: January 2023

Infective endocarditis is a relatively uncommon infection that requires a high index of suspicion, which can sometimes delay its diagnosis. It requires several weeks of intravenous antibiotics, which traditionally requires long hospital stays. Dalbavancin is a novel antibiotic with high activity against several Gram-positive pathogens. Its weekly administration allows the outpatient management of complicated infections requiring parenteral treatment, but only a few cases of Enterococcus faecalis endocarditis treated with dalbavancin have been reported in the literature. We here report a case of successful treatment with dalbavancin of an infectious endocarditis caused by E. faecalis.
The pathophysiology, assessment, and management of acute pain
Authors: Mears Lyndsey , Mears John
Published: January 2023

This article reviews the pathophysiology and treatment of acute pain. Two definitions of pain are considered, along with the International Association for the Study of Pain taxonomy for nociceptive, neuropathic and nociplastic pain. The mechanisms of acute and neuropathic pain are considered. Methods of assessment are discussed followed by the pharmacological management of both nociceptive and neuropathic pain.
Level 2 clinical supervision for community practitioners working with palliative and end-of-life care patients
Authors: Kingsley Marc J , Hussain Feryad , Ma Rumin
Published: January 2023

Background: Little has been written on the availability of specialist level 2 supervision groups to support community practitioners regarding the emotional components of their palliative and end-of-life caseload. Adapted level 2 groups (AL2Gs) have been piloted in three community teams in the NHS to address this. Aims: This study aimed to evaluate whether access to AL2Gs benefited community palliative and end-of-life practitioners at three sites. The outcomes for those who attended and those unable to attend were considered. Findings: Attendees found AL2Gs beneficial, reporting better confidence and wellbeing, plus a sense of containment through group cohesion and trust in the facilitators and fellow AL2G members. Most would recommend the groups to all staff working in community palliative care. Practitioners who were not able to attend relied on informal and ad-hoc peer support, and had concerns about their skills in managing patients’ psychological needs. Conclusion: Community nurses benefit from attending AL2Gs to support them with their palliative care/end-of-life caseloads. It is recommended that all community staff involved in this type of care have access to regular clinical supervision, especially in a group format.
Evaluation of the difficult intravenous access (DIVA) scoring in hospitalized pediatric patients
Authors: Kanaley Rebecca L , Gillette Cheryl , Schriefer Jan , Gottfried Julie Albright , Bramley John
Published: January 2023

HIGHLIGHTS

The DIVA scoring tool has previously been validated in the pediatric ED setting. Our project applied DIVA to an inpatient pediatric sample. DIVA may not predict likelihood of PIV success in the inpatient setting.

Background: First-attempt success rate for placing pediatric peripheral intravenous (PIV) catheters ranges from to 24% to 52%. Multiple attempts can increase risk of deleterious outcomes. It is essential to screen pediatric patients appropriately to identify those who will require additional resources for successful PIV placement. Methods: A convenience sample of hospitalized pediatric patients 0 to 18 years of age on a general care unit was used in this performance improvement project. Prior to attempting PIV access, nurses completed a data collection tool that included elements of established difficult intravenous access (DIVA) tools as well as first attempt successful PIV placement. The primary outcome measure was to determine if each DIVA scoring tool is accurate in predicting the need for additional resources to achieve successful first-attempt PIV placement. The secondary outcome measure was to compare the predictive value of each DIVA scoring tool among an inpatient pediatric population. Following data exploration and cleaning, a correlation analysis was performed with logistic regression to assess DIVA score effectiveness in predicting success of PIV insertion on the first attempt. Results: Out of 133 children, 167 PIV attempts were analyzed with 150 PIV attempts included in the final data analysis. Of the 150 PIV attempts analyzed, 60% (n=90) were successful on the first attempt. Performance of prediction for first-time insertion success was comparable among all 4 DIVA scoring tools. Conclusions: None of the 4 DIVA scoring tools were superior in predicting first-time PIV placement among hospitalized children. Vein palpability was more predictive, although not statistically significant.
Care as work: ayahs and eldercare practices in India
Authors: Choudhury Ahana , Das Amiya Kumar
Published: January 2023

Eldercare arrangements are intricately woven and complex. While adult children are socially extolled as legitimate caregivers, ayahs working in ayah centres are making revolutionary strides in Kolkata. Drawing across this context, the article explores multiple essences of lived experiences through which care actors like ayahs, elderly care receivers, their kin and ayah-centre managers produce and reproduce ‘care practices’. These establish ayahs and ayah centres as a social resource for the elderly, enabling them to reflect on their mundane ageing and ‘personhood’ in Kolkata.
The Role of Information and Knowledge in COVID-19 Vaccination Among People With Intellectual and Developmental Disabilities and Their Families
Authors: Lineberry Sarah , Bogenschutz Matthew , Dinora Parthenia , Ayers Kara
Published: January 2023

People with intellectual and developmental disabilities (IDD) may be at an increased risk of severe illness and death from COVID-19. This article examines the role of information and knowledge in COVID-19 vaccine uptake for people with IDD and their families. We developed a survey about COVID-19 vaccine uptake, confidence, and knowledge for people with IDD and their families. COVID-19 vaccine uptake was associated with higher self-reported knowledge about the vaccine, learning about the vaccine from one's doctor, and social media use. Qualitative results reflected the importance of trusted relationships with medical providers in vaccination.
Optical limiting in multilayer graphene films on a cobalt buffer-layer produced by the sputtering technique
Authors: Barreto Luiz M. M. , da Silva Davinson M. , Santos Antonio D. , Araki Koiti , de Araújo Cid B. , Kassab Luciana R. P.
Published: January 2023

Multilayer graphene (MLG) thin films were produced by a sputtering technique on a cobalt buffer-layer prepared at 500°C and thermal annealed after the deposition. The transformation of amorphous carbon (C) to graphene occurs by diffusion of C atoms through the catalyst metal; then the C atoms dissolved in the metal are nucleated as graphene. The thicknesses of cobalt and MLG thin films were 55 and 54 nm, respectively, obtained by atomic force microscopy (AFM). Raman spectroscopy showed that the ratio between the Raman bands 2D and G (I2D/IG) was 0.4 for the graphene thin film that was annealed at 750°C for 25 min, indicating that the films obtained are MLG. The Raman results were corroborated by transmission electron microscopy analysis. AFM was used to determine the Co and C film thickness and roughness. Transmittance measurements at 980 nm as a function of input power from a continuous-wave diode laser showed that the obtained MLG films present large nonlinear absorption and can be used as optical limiters.
Mode conversion between fibers with different refraction index distribution based on adiabatically tapered structures
Authors: Zhou Xuanfeng
Published: January 2023

Different fibers generally have different mode characteristics so their connections in many practical applications often require mode conversion. The feasibility of mode conversion between fibers with different refractive index distributions based on adiabatically tapered structures is theoretically analyzed. The first kind of mode conversion is between ring core fiber and convex core fiber; the second kind is between multicore fiber and single-core fiber. Three common tapered structures are investigated: tapered core, diffused core, and tapered cladding. The analysis results show that mode conversion by a tapered structure is not suitable for all the modes for a ring core fiber and a convex core fiber; however, it can be accomplished for multicore fiber and single-core fiber.
Multiplexed digital volume reflection holograms generated from digital transmission holograms
Authors: Qissi Saleha , Banerjee Partha P.
Published: January 2023

Interference from co-propagation of the object and reference beams can be digitally recorded for a digital transmission hologram (DTH). Volume holograms, as in display holography, which have been traditionally recorded in bulk photopolymer or photorefractive materials using a counter-propagating object and writing beams, are read out using multispectral light and offer the advantage of excellent wavelength selectivity. In this work, the reconstruction from a single digital volume reflection hologram (DVRH) and wavelength multiplexed DVRHs derived from respective single and multi-wavelength DTHs is investigated, using coupled wave theory and an angular spectral approach. The dependence of the diffraction efficiency on volume grating thickness, wavelength, and incident angle of the reading beam is studied.
Development and verification of the signal to noise ratio for a layer of turbulence in a multi-layer atmosphere
Authors: Hamilton R. J. , Hart Michael
Published: January 2023

Wide-field image correction in systems that look through the atmosphere
generally requires a tomographic reconstruction of the turbulence
volume to compensate for anisoplanatism. The reconstruction is
conditioned by estimating the turbulence volume as a profile of thin
homogeneous layers. We present the signal to noise ratio (SNR) of a
layer, which quantifies how difficult a single layer of homogeneous
turbulence is to detect with wavefront slope measurements. The signal
is the sum of wavefront tip and tilt variances at the signal layer,
and the noise is the sum of wavefront tip and tilt auto-correlations
given the aperture shape and projected aperture separations at all
non-signal layers. An analytic expression for layer SNR is found for
Kolmogorov and von Kármán turbulence models, then
verified with a Monte Carlo simulation. We show that the Kolmogorov
layer SNR is a function of only layer Fried length, the spatio-angular
sampling of the system, and normalized aperture separation at the
layer. In addition to these parameters, the von Kármán
layer SNR also depends on aperture size, and layer inner and outer
scales. Due to the infinite outer scale, layers of Kolmogorov
turbulence tend to have lower SNR than von Kármán
layers. We conclude that the layer SNR is a statistically valid
performance metric to be used when designing, simulating, operating,
and quantifying the performance of any system that measures properties
of layers of turbulence in the atmosphere from slope data.
Research on the computational method of creeping waves diffraction of arbitrary complex target based on the planar mesh model
Authors: Huang Qi , He Siyuan , Zhang Yunhua , Zhu Guoqiang , Chen Haitao
Published: January 2023

For a long time, due to the difficulty of obtaining accurate propagation trajectories, the research on creeping waves is limited to canonical geometries or simple targets, which leads to the situation that it is relatively mature in theoretical research on creeping waves, while the practical application scope of creeping waves for complex targets is narrow. In this paper, a thorough electromagnetic computation method for creeping waves on complex planar mesh model is systematically proposed. This approach broadens the field of creeping waves applications due to the generality of planar mesh models in electromagnetic engineering. The contents consist of the tracing of creeping waves, the calculation of the diffraction field, and the coupling effect with other scattering mechanisms. Aiming at the trajectory of creeping waves, we propose a set of tracing algorithms that enable rapid, real-time tracing based on analytical geometry and related computer graphics algorithms. Utilizing information such as vertices, triangles, and topological relations in the mesh model, one can recover the mathematical properties of the surfaces of the model and then, the corresponding parameters can be obtained. Therefore, the uniform geometrical theory of diffraction (UTD) can be used to accurately calculate the diffraction field. Moreover, for complex targets, the multiple coupling effect caused by creeping waves is the main source of radar echoes in many cases, which is not unimportant. Hence based on the electromagnetic accurate modeling, the coupling mechanism of creeping waves and various scattering mechanisms are studied. The research content is expected to have high application values in target recognition and characteristics.
Engineering and detection of light scattering directionalities in dewetted nanoresonators through dark-field scanning microscopy
Authors: Granchi Nicoletta , Fagiani Luca , Salvalaglio Marco , Barri Chiara , Ristori Andrea , Montanari Michele , Gurioli Massimo , Abbarchi Marco , Voigt Axel , Vincenti Maria Antonietta , Intonti Francesca , Bollani Monica
Published: January 2023

Dewetted, SiGe nanoparticles have been successfully exploited for light management in the visible and near-infrared, although their scattering properties have been so far only qualitatively studied. Here, we demonstrate that the Mie resonances sustained by a SiGe-based nanoantenna under tilted illumination, can generate radiation patterns in different directions. We introduce a novel dark-field microscopy setup that exploits the movement of the nanoantenna under the objective lens to spectrally isolate Mie resonances contribution to the total scattering cross-section during the same measurement. The knowledge of islands’ aspect ratio is then benchmarked by 3D, anisotropic phase-field simulations and contributes to a correct interpretation of the experimental data.
High-security 3D CAP modulation scheme based on a pyramid constellation design for 7-core fiber
Authors: Xia Wenchao , Liu Bo , Ren Jianxin , Ullah Rahat , Wu Xiangyu , Mao Yaya , Ma Yiming , Chen Shuaidong , Wan Yibin , Zhong Qin , Zhao Jianye , Bai Yu , Yuan Tingxuan , Zhao Lilong
Published: January 2023

This paper proposes a 3-dimensional (3D) carrier-less amplitude and phase modulation (CAP) based on a pyramid constellation design encryption scheme for 7-core fiber in passive optical network (PON). The chaos sequences generated by the 4D hyperchaotic system are applied to produce the masking factor, and the pyramid Rubik's cube rotation rules are used to flip and rotate the constellation points. To verify the performance of the proposed 3D CAP-PON system, 25.5Gb/s encrypted Pyraminx-3D-CAP-16 signal transmission over 2 km 7-core fiber is experimentally demonstrated. Compared with the traditional 3D-CAP-16 signal, the proposed Pyraminx-3D-CAP-16 signal achieves a sensitivity gain of 0.5 dB under the limit of hard decision forward error correction (HD-FEC) 3.8 × 10−3. Compared with the Pyraminx-3D-CAP-16 signal, the encrypted Pyraminx-3D-CAP-16 signal has little difference from that before encryption, which has a great application prospect in the physical layer security enhancement of the 3D-CAP-PON system.
Ferroelectric domain engineering with femtosecond pulses of different wavelengths
Authors: Wang Sen , Liu Shan , Liu Dawei , Wang Ningning , Zhao Ruwei , Liu Yongxing , Li Ziliang , Mao Guangrui , Chen Feifei , Sheng Yan , Xu Tianxiang , Krolikowski Wieslaw
Published: January 2023

Direct femtosecond laser writing of ferroelectric domain structures has been an indispensable technique for engineering the second-order optical nonlinearity of materials in three dimensions. It utilizes localized thermoelectric field motivated by nonlinear absorption at the position of laser focus to manipulate domains. However, the impact of laser wavelengths, which is pivotal in nonlinear absorption, on the inverted domains is still sketchy. Herein, the light-induced ferroelectric domain inversion is experimentally studied. It is shown that the domain inversions can be achieved over a broad spectral range, but the optical threshold for domain inversion varies dramatically with the laser wavelength, which can be explained by considering the physical mechanism of femtosecond laser poling and nonlinear absorption properties of the crystal. Meanwhile, the effects of other laser processing parameters are also experimentally investigated. Our findings are useful to guide the fabrication of high-performance optical and electronic devices based on ferroelectric domains.
Simultaneous measurement of carbon emission and gas temperature via laser-induced breakdown spectroscopy coupled with machine learning
Authors: Kim Dongju , Bong Cheolwoo , Im Seong-kyun , Bak Moon Soo
Published: January 2023

A method, which can accurately measure carbon emission and gas temperature simultaneously in real-time from a laser-induced breakdown spectrum (LIBS) via machine learning, is proposed in this study. In typical, peak intensity ratios had been used to map species concentrations prior to plasma formation, after removing the broadband continuum of the spectrum; however, the dependence of these peak intensity ratios on the concentration changes with the change in gas density. Therefore, considering the fact that the strength and shape of this broadband continuum is a function of the gas density for a given optical setup, we attempted to collect a spectrum by shortening the time delay after the laser fire, such that the spectrum can contain some of the broadband continuum. Since the analytical quantification of this broadband continuum is not trivial, we employed a machine learning approach to acquire a model that simultaneously predicts the gas temperature and CO2 concentration. The predictive performance of the model trained with spectra that contain the broadband continuum was much better than that without it; the gradient-weighted regression activation mapping (Grad-RAM) analysis revealed that the model utilizes the broadband spectrum for temperature prediction and correction of changes in peak intensity due to temperature changes in the concentration prediction process.
Generation of 17–32 THz radiation from a CdSiP2 crystal
Authors: Carnio B. N. , Zawilski K. T. , Schunemann P. G. , Moutanabbir O. , Elezzabi A. Y.
Published: January 2023

A phase-resolved electric field pulse is produced through the second-order nonlinear process of intra-pulse difference frequency generation (DFG) in a (110) CdSiP2 chalcopyrite crystal. The generated electric field pulse exhibits a duration of several picoseconds and contains frequency components within the high-frequency terahertz regime of ∼17–32 THz. The intra-pulse DFG signal is shown to be influenced by single-phonon and two-phonon absorption, the nonlinear phase-matching criterion, and temporal spreading of the excitation electric field pulse. To date, this is the first investigation in which a CdSiP2 chalcopyrite crystal is used to produce radiation within the aforementioned spectral range.
Gamma-radiation enhancement of sensing properties of FBGs in a few-mode polymer CYTOP fiber
Authors: Chapalo Ivan , Chah Karima , Gusarov Andrei , Ioannou Andreas , Pospori Andreas , Nan Ying-Gang , Kalli Kyriacos , Mégret Patrice
Published: January 2023

We investigate the effect of γ-radiation on temperature (T) and relative humidity (RH) sensitivities of polymer perfluorinated fiber Bragg gratings (FBGs). To this aim, different γ-radiation doses (80, 120, 160, and 520 kGy) were applied to a set of FBGs. We show that irradiated FBGs demonstrate an RH sensitivity rise with the received dose: from 13.3 pm/%RH for a pristine FBG up to 56.8 pm/%RH for a 520-kGy dose at 30℃. In contrast, T sensitivity decreases with radiation dose with a subsequent change of sign from positive to negative. Therefore, by experimental interpolation, T sensitivity can be eliminated at around a 160-kGy dose. This opens the possibility of designing an RH sensor with enhanced sensitivity, which at the same time is insensitive to T.
Ultracompact terahertz plasmonic mode division multiplexer
Authors: Ma Xinyu , Li Yanfeng , Han Jiaguang
Published: January 2023

In this Letter, an ultracompact terahertz (THz) mode division multiplexer based on THz spoof surface plasmon polaritons (SPPs) is proposed. Compared with traditional optical multiplexing devices, the proposed mode multiplexer can be designed with a reduced footprint by exploiting more degrees of freedom in the parameters of the unit cell, namely a rectangular metallic pillar. The ultracompact mode division multiplexer can simultaneously support the propagation of four mode channels: the TM0, TM1, TM2, and TM3 modes. Then, we numerically evaluate the performance of a cascaded plasmonic mode division circuit composed of a mode multiplexer and demultiplexer. The cross talk and excess loss of the whole circuit are lower than –15 dB and 3.7 dB, respectively, for all four mode channels at a center frequency of 0.65 THz. The footprint of the whole device is about 27 × 2.3 mm and the length of each coupling region is about 2.7 mm. For the first time, to the best of our knowledge, a mode division multiplexer based on THz spoof SPPs is reported, which will form core devices for future THz on-chip multimode communication systems.
Dispersion controlled nanocomposite gradient index lenses
Authors: Williams George M. , Paul Harmon J.
Published: January 2023

The degrees of freedom afforded by nanocomposite materials and additive manufacturing allow for the precise control over the chromatic properties of gradient index (GRIN) optics. The ability to engineer nanocomposite optical materials using blends of three or more constituents makes it possible to independently specify the refractive index gradient and the dispersion of optical materials. The refractive index spectra of the primary nanocomposite feedstock are defined relative to one another using various concentrations of monomers and nanofillers. Inkjet deposition is then used to print-compose specific feedstock to form refractive index gradients with precise control over dispersion. Arrays of 4-mm-diameter spherical GRIN lenses were fabricated using different nanomaterial compositions. The ability to positively and negatively control dispersion and to obtain achromatic performance was demonstrated. Control over partial dispersion is also shown.