bluuebunny/crossref_metadata_2025 huggingface dataset:
Time-lapse difference inversion based on the modified reflectivity method with differentiable hyper-Laplacian blocky constraint
Authors: Tang Wei , Li Jingye , Zhang Wenbiao , Zhang Jian , Geng Weiheng , Li Yuanqiang
Published: August 2021

Time-lapse (TL) seismic has great potential in monitoring and interpreting time-varying variations in reservoir fluid properties during hydrocarbon exploitation. Obtaining the disparities of reservoir elastic parameters by inversion is essential for TL reservoir monitoring. Conventional TL inversion is carried out by stages without coupling processing and leads to inaccurate results. We directly use the differences in seismic data responses from different vintages, namely, difference inversion, to improve the results’ credibility. It may reduce the deviations of the subtraction of base and monitor inversions in traditional methods. Moreover, most existing studies involving prestack inversion methods use the Zoeppritz equation or its approximants, which failed to consider the wave-propagation effects. We have developed a new TL difference inversion based on the modified reflectivity method (MRM), in which the internal multiples and transmission losses are taken into consideration to fine-tune the characterization of the seismic wave propagating underground. The new method is modified on the basis of the reflectivity method making it feasible in TL difference inversion, and it is derived from the Bayesian theorem. For further delineating the boundaries between layers, the differentiable hyper-Laplacian blocky constraint (DHLBC) is introduced into the prior information of a Bayesian framework, which heightens the sparseness in the vertical gradients of the inversion results and leads to sharp interlayer boundaries of the difference parameters. Synthetic and field data experiments demonstrate that our TL difference inversion method has clear advantages in accuracy and resolution compared with the Zoeppritz method and MRM without DHLBC.
Increasing access to cognitive–behavioural therapy for patients with psychosis by evaluating the feasibility of a randomised controlled trial of brief, targeted cognitive–behavioural therapy for distressing voices delivered by assistant psychologists: the GiVE2 trial
Authors: Hayward Mark , Berry Katherine , Bremner Stephen , Jones Anna-Marie , Robertson Sam , Cavanagh Kate , Gage Heather , Berry Clio , Neumann Suzanne , Hazell Cassie M , Fowler David , Greenwood Kathryn , Strauss Clara
Published: August 2021

Background

Cognitive–behavioural therapy (CBT) is recommended for all patients with psychosis, but is offered to only a minority. This is attributable, in part, to the resource-intensive nature of CBT for psychosis. Responses have included the development of CBT for psychosis in brief and targeted formats, and its delivery by briefly trained therapists. This study explored a combination of these responses by investigating a brief, CBT-informed intervention targeted at distressing voices (the GiVE intervention) administered by a briefly trained workforce of assistant psychologists.

Aims

To explore the feasibility of conducting a randomised controlled trial to evaluate the clinical and cost-effectiveness of the GiVE intervention when delivered by assistant psychologists to patients with psychosis.

Method

This was a three-arm, feasibility, randomised controlled trial comparing the GiVE intervention, a supportive counselling intervention and treatment as usual, recruiting across two sites, with 1:1:1 allocation and blind post-treatment and follow-up assessments.

Results

Feasibility outcomes were favourable with regard to the recruitment and retention of participants and the adherence of assistant psychologists to therapy and supervision protocols. For the candidate primary outcomes, estimated effects were in favour of GiVE compared with supportive counselling and treatment as usual at post-treatment. At follow-up, estimated effects were in favour of supportive counselling compared with GiVE and treatment as usual, and GiVE compared with treatment as usual.

Conclusions

A definitive trial of the GiVE intervention, delivered by assistant psychologists, is feasible. Adaptations to the GiVE intervention and the design of any future trials may be necessary.
Exploring factors in fear of COVID-19 and its GIS-based nationwide distribution: the case of Bangladesh
Authors: Mamun Mohammed A.
Published: August 2021

Background

The COVID-19 pandemic is a public health threat of international concern, intensifying peoples’ psychological risk and vulnerability by strengthening mental health stressors such as fear, panic and uncertainty. The unexpected fear of COVID-19 has been reported to be associated with suicide occurrences, similar to prior pandemics.

Aims

Identifying the factors associated with fear of COVID-19 could help us to develop better mental health strategy and practice to improve the situation here in Bangladesh. This was the first attempt to present a Geographic Information System (GIS)-based distribution of fear of COVID-19 across the country's administrative districts in a nationwide sample.

Method

Data for a total of 10 067 individuals were collected by an online survey during the first wave of the pandemic (1 to 10 April 2020); data for 10 052 participants were finally analysed after excluding 15 transgender individuals. The survey questionnaire included items concerning sociodemographic, behavioural and health-related variables, COVID-19-related issues, and the Bangla Fear of COVID-19 Scale.

Results

The mean fear of COVID-19 scores was 21.30 ± 6.01 (out of a possible 35) in the present sample. Female gender, highly educated, non-smoker, non-alcohol consumer, having chronic diseases, using social media, and using social media and not using newspapers as COVID-19 information sources were associated with a higher level of fear of COVID-19. Higher levels of fear of COVID-19 were found in districts of Magura, Panchagarh, Tangail, Sunamganj and Munshiganj; by contrast, Kushtia, Pirojpur, Chapainawabganj, Jhalokathi and Naogaon districts had lower fear of COVID-19. Based on the GIS-distribution, fear of COVID-19 was significantly associated with the district as well as in respect to its gender-based and education-level-based associations. However, fear of COVID-19 and COVID-19 cases were heterogeneously distributed across the districts; that is, no consistent association of higher COVID-19 cases with higher fear of COVID-19 was found.

Conclusions

This study being exploratory in nature may help to facilitate further studies, as well as directing governmental initiatives for reducing fear of COVID-19 in at-risk individuals. Providing adequate resources and mental health services in the administrative regions identified as highly vulnerable to fear of COVID-19 is recommended.
Association between air pollution exposure and mental health service use among individuals with first presentations of psychotic and mood disorders: retrospective cohort study
Authors: Newbury Joanne B. , Stewart Robert , Fisher Helen L. , Beevers Sean , Dajnak David , Broadbent Matthew , Pritchard Megan , Shiode Narushige , Heslin Margaret , Hammoud Ryan , Hotopf Matthew , Hatch Stephani L. , Mudway Ian S. , Bakolis Ioannis
Published: August 2021

Background

Growing evidence suggests that air pollution exposure may adversely affect the brain and increase risk for psychiatric disorders such as schizophrenia and depression. However, little is known about the potential role of air pollution in severity and relapse following illness onset.

Aims

To examine the longitudinal association between residential air pollution exposure and mental health service use (an indicator of illness severity and relapse) among individuals with first presentations of psychotic and mood disorders.

Method

We identified individuals aged ≥15 years who had first contact with the South London and Maudsley NHS Foundation Trust for psychotic and mood disorders in 2008–2012 (n = 13 887). High-resolution (20 × 20 m) estimates of nitrogen dioxide (NO2), nitrogen oxides (NOx) and particulate matter (PM2.5 and PM10) levels in ambient air were linked to residential addresses. In-patient days and community mental health service (CMHS) events were recorded over 1-year and 7-year follow-up periods.

Results

Following covariate adjustment, interquartile range increases in NO2, NOx and PM2.5 were associated with 18% (95% CI 5–34%), 18% (95% CI 5–34%) and 11% (95% CI 3–19%) increased risk for in-patient days after 1 year. Similarly, interquartile range increases in NO2, NOx, PM2.5 and PM10 were associated with 32% (95% CI 25–38%), 31% (95% CI 24–37%), 7% (95% CI 4–11%) and 9% (95% CI 5–14%) increased risk for CMHS events after 1 year. Associations persisted after 7 years.

Conclusions

Residential air pollution exposure is associated with increased mental health service use among people recently diagnosed with psychotic and mood disorders. Assuming causality, interventions to reduce air pollution exposure could improve mental health prognoses and reduce healthcare costs.
Genomic Profiling of Combined Hepatocellular Cholangiocarcinoma Reveals Genomics Similar to Either Hepatocellular Carcinoma or Cholangiocarcinoma
Authors: Murugesan Karthikeyan , Sharaf Radwa , Montesion Meagan , Moore Jay A. , Pao James , Pavlick Dean C. , Frampton Garrett M. , Upadhyay Vivek A. , Alexander Brian M. , Miller Vincent A. , Javle Milind M. , Bekaii Saab Tanios S. , Albacker Lee A. , Ross Jeffrey S. , Ali Siraj M.
Published: August 2021

PURPOSE

Combined hepatocellular cholangiocarcinoma (cHCC-CCA) is a rare, aggressive primary liver carcinoma, with morphologic features of both hepatocellular carcinomas (HCC) and liver cholangiocarcinomas (CCA).

METHODS

The genomic profiles of 4,975 CCA, 1,470 HCC, and 73 cHCC-CCA cases arising from comprehensive genomic profiling in the course of clinical care were reviewed for genomic alterations (GA), tumor mutational burden, microsatellite instability status, genomic loss of heterozygosity, chromosomal aneuploidy, genomic ancestry, and hepatitis B virus status.

RESULTS

In cHCC-CCA, GA were most common in TP53 (65.8%), TERT (49.3%), and PTEN (9.6%), and 24.6% cHCC-CCA harbored potentially targetable GA. Other GA were predominantly associated with either HCC or CCA, including, but not limited to, TERT, FGFR2, IDH1, and presence of hepatitis B virus. On the basis of these features, a machine learning (ML) model was trained to classify a cHCC-CCA case as CCA-like or HCC-like. Of cHCC-CCA cases, 16% (12/73) were ML-classified as CCA-like and 58% (42/73) cHCC-CCA were ML-classified as HCC-like. The ML model classified more than 70% of cHCC-CCA as CCA-like or HCC-like on the basis of genomic profiles, without additional clinico-pathologic input.

CONCLUSION

These findings demonstrate the use of ML for classification as based on a targeted exome panel used during routine clinical care. Classification of cHCC-CCA by genomic features alone creates insights into the biology of the disease and warrants further investigation for relevance to clinical care.
Unbiased K-L estimator for the linear regression model
Authors: Aladeitan BENEDICTA , Lukman Adewale F , Davids Esther , Oranye Ebele H , Kibria Golam B M
Published: August 2021

Background:In the linear regression model, the ordinary least square (OLS) estimator performance drops when multicollinearity is present. According to the Gauss-Markov theorem, the estimator remains unbiased when there is multicollinearity, but the variance of its regression estimates become inflated. Estimators such as the ridge regression estimator and the K-L estimators were adopted as substitutes to the OLS estimator to overcome the problem of multicollinearity in the linear regression model. However, the estimators are biased, though they possess a smaller mean squared error when compared to the OLS estimator.

Methods: In this study, we developed a new unbiased estimator using the K-L estimator and compared its performance with some existing estimators theoretically, simulation wise and by adopting real-life data.

Results:Theoretically, the estimator even though unbiased also possesses a minimum variance when compared with other estimators.  Results from simulation and real-life study showed that the new estimator produced smaller mean square error (MSE) and had the smallest mean square prediction error (MSPE). This further strengthened the findings of the theoretical comparison using both the MSE and the MSPE as criterion.

Conclusions:By simulation and using a real-life application that focuses on modelling, the high heating values of proximate analysis was conducted to support the theoretical findings. This new method of estimation is recommended for parameter estimation with and without multicollinearity in a linear regression model.
Case Report: Cyclophosphamide in COVID-19 – when an absolute contraindication is an absolute necessity
Authors: Bołtuć Kamila , Bielejewska Ada , Coloma-Millar Alejandro , Dziugieł Robert , Bociek Arkadiusz , Perkowska-Ptasińska Agnieszka , Jaroszyński Andrzej
Published: August 2021

Background: Despite many studies on COVID-19, our knowledge of it remains incomplete. In some cases, treating SARS-CoV-2 infection concomitant with other diseases can be particularly challenging, as finding an appropriate treatment may involve some risks.

Case presentation: A 34-year-old SARS-CoV-2 positive patient admitted due to fever, dyspnoea, haemoptysis and pneumonia, developed alveolar haemorrhage and acute kidney injury. Due to his severe state, abnormalities in laboratory tests and rapidly progressing loss of kidney function, kidney biopsy, as well as antibody panel were carried out, in which perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCA) were found with a high titer (>200; N: <1:20). The results of kidney biopsy, combined with clinical manifestation and laboratory findings prompted the diagnosis of rapidly progressing glomerulonephritis (RPGN) in the course of p-ANCA vasculitis. Initial treatment consisted of heamodialyses, remdesivir, plasmaphereses, intravenous immunoglobulins, antibiotics, corticosteroids and fraxiparine. Once the haemorrhage had subsided, kidney function had been partially retrieved and heamodialyses had no longer been necessary, cyclophosphamide treatment was initiated, despite being contraindicated in COVID-19 according to its summary of product characteristics. Immunotherapy is still continued. The patient has already received a total of 2.4g of cyclophosphamide (4 cycles of 600mg each every three weeks). Pulmonary and radiological regression, as well as improvement of renal parameters have been achieved.       

Conclusions: We suspect that cyclophosphamide, the drug of choice in p-ANCA vasculitis, could be a potential factor providing regression of the radiological changes in the lungs and it could have prevented the patient from developing acute respiratory distress syndrome. COVID-19 diagnosis should not exclude searching for other diseases which can have a similar course. When treating a patient in a life-threatening condition, a departure from trying to find the perfect timing of cyclophosphamide delivery should be considered, as delaying it could cause potentially greater harm.
Pediatric Calcaneal Tuberosity Avulsion Fracture: A Case Report and Literature Review
Authors: Saleh Ehab S , Elabd Ahmed
Published: August 2021

Introduction: Calcaneus fractures are rare in the pediatric population, and avulsion fracture of the calcaneal tuberosity is even less common. In adults, those fractures are usually associated with poor bone quality, however, this is not the case in children. It is a fracture that requires emergent intervention to prevent devastating skin and soft-tissue-related complications.
Case Report: We report a case of a 9-year-old female who had a displaced calcaneal tuberosity fracture with heel skin impending compromise, after a fall at an indoor gymnastic facility. The child had a history of acute lymphoblastic leukemia, diagnosed at age 4, she was in remission at the time of injury. In the present report, besides reporting a rare injury among the pediatric population, we also describe the operative management, the post-operative course, and we review the literature.
Conclusion: Pediatric calcaneal tuberosity fractures, although rare, can lead to devastating complications if not addressed promptly, and should be treated in an expedited fashion.
Keywords: Pediatric, calcaneal tuberosity, skin compromise.
Absence of Flexor Carpi Radialis Identified During Volar Approach for Fixation of Distal Radius Fracture: A Case Report
Authors: Patel Dharmesh , Vohra Rajeev , Singh Avtar
Published: August 2021

Introduction: Volar locking plate fixation of distal radius fractures is commonly performed because of its good clinical outcomes. The flexor carpi radialis (FCR) approach is one of the most popular approaches to dissecting the volar side of the distal radius because of its simplicity and safety. We describe an extremely rare case of an absent FCR identified during a volar approach for fixation of a distal radius fracture.
Case Report: A 40-year-old male with comminuted distal radius fracture underwent surgery using the usual FCR approach and volar locking plate. We could not identify the absence of the FCR tendon preoperatively because of severe swelling of the distal forearm. At first, we wrongly identified the palmaris longus (PL) tendon as the FCR because it was the tendinous structure at the most radial location of the volar distal forearm. When we found the median nerve just radial to the PL tendon, we were then able to identify the anatomical abnormality in this case. To avoid iatrogenic neurovascular injuries, we changed the approach to the classic Henry’s approach.
Conclusion: Although the FCR approach is commonly used for fixation of distal radius fractures because of its simplicity and safety, this is the first report of complete absence of the FCR during the commonly performed volar approach for fixation of a distal radius fracture, to our knowledge. Because the FCR is designated as a favorable landmark because of its superficially palpable location, strong and thick structure, and rare anatomical variations, there is the possibility of iatrogenic complications in cases of the absence of the FCR. We suggest that surgeons should have a detailed knowledge of the range of possible anomalies to complete the fixation of a distal radius fracture safely.
Keywords: Flexor carpi radialis, Anomaly, Distal radius fracture, Volar approach, Flexor carpi radialis approach.
Bilateral Osteochondritis Dissecans of the Talar Posterior Calcaneal Articular Surface in a Professional Soccer Player: A Case Report
Authors: Yanagisawa Yohei , Ishii Tomoo , Yamazaki Masashi
Published: August 2021

Introduction: Preferred sites of osteochondritis dissecans (OCD) are the distal femur and humerus, and the dome of the talus. We report a rare case of a professional soccer player with bilateral OCD of the talar posterior calcaneal articular surface.
Case Report: The left talus showed a loose but not displaced fragment, and pain was relieved with 3 months of conservative treatment. The right had two loose fragments that were displaced from their beds in the talar posterior calcaneal articular surface. The loose bodies were surgically excised. The player remains symptom free 4 years after the operation and participates in professional games. Thus, although OCD of the talar posterior calcaneal articular surface remains a relatively uncommon injury, we suggest that treatment methods tailored to the OCD stage as per Berndt and Harty classification may be successful. The exact causes and establishment of a treatment protocol in these cases will depend on the investigation of future cases.
Conclusion: Since this case of OCD of the talar posterior calcaneal articular surface was bilateral, we hypothesized that it may have been caused by microtrauma in the sense of repetitive, excessive compression of the subchondral bone, or by a vascular etiology.
Keywords: Case report, lateral hindfoot pain, osteochondral lesion, subtalar articular facet, subtalar joint.
Recurrent Methotrexate-related Lymphoproliferative Disorder of the Lumbar Spine Origin: A Case Report
Authors: Okuwaki Shun , Uesugi Masafumi , Koda Masao , Kikuchi Naoya , Yamazaki Masashi
Published: August 2021

Introduction: Previously, we reported a relatively rare case of methotrexate-related lymphoproliferative disorder (MTX-LPD) that developed in the lumbar spine. At present, we report the follow-up of that case, presenting with relapse of MTX-LPD.
Case Report: The participant was a 75-year-old woman who was diagnosed with MTX-LPD of the lumbar spine and in whom remission was obtained 6 months after discontinuing methotrexate (MTX). At 12 months after remission, elevated levels of soluble interleukin-2 receptor, lymph node swelling on plain computed tomography (CT), and fluorodeoxyglucose uptake on positron emission tomography CT were observed, and recurrent MTX-LPD was diagnosed. Doxorubicin, bleomycin, vinblastine, and dacarbazine therapy was initiated, and partial remission was obtained 6 months later.
Conclusion: In MTX-LPD, remission is often achieved following discontinuation of MTX alone; however, some patients do not improve, and some patients relapse, as seen in the present case. Such cases are treated using the standard regimen for the observed histologic subtype. Even after remission has been achieved, strict follow-up observation is needed for MTX-LPD. Furthermore, when signs of recurrence are observed during follow-up, practitioners should endeavor to cooperate with other specialists and act without delay.
Keywords: Rheumatoid arthritis, methotrexate, lymphoproliferative disorder, lumbar spine, oncology.
Case Report of a Rare Cause of Reactive Arthritis: Leptospirosis
Authors: Dey Sudipan , Sipani Arun Kumar , Das Rajdeep
Published: August 2021

Introduction: Leptospirosis is a zoonosis caused by infection with pathogenic Leptospira species. Leptospirosis has protean manifestations and rare, unusual presentations should be kept in mind in relevant epidemiological scenario. Reactive arthritis refers to acute non-purulent arthritis complicating an infection elsewhere in the body. It is attributed to an immune activation following certain infections; it is, therefore considered as aseptic arthritis. Very few case reports are available attributing leptospirosis as an established cause of reactive arthritis. We present a case of reactive arthritis of the hip joint due to leptospirosis.
Case Report: Here, we present a case of a 12-years- old female child who was admitted to our hospital with complaints of fever, headache, and pain in the right hip joint since past 5 days from admission. Subsequent elaboration revealed a past history of fever, headache, and myalgia for around 5-7 days around a week before the present complaints. There was rat infestation near her house and her father was working as sewage cleaner. Routine investigations, Ultrasonography (USG), Magnetic Resonance Imaging (MRI) of both hips and subsequently, diagnostic hip aspiration was performed. USG revealed synovitis, MRI revealed hip joint arthritis of infective or inflammatory origin. Diagnostic hip aspiration was negative for any microorganism. On 10th day of admission, patient started developing icterus with yellowish discolouration of urine. Patient was evaluated for the cause of jaundice. Screening for Leptospira was positive. Synovial biopsy of hip was performed, which showed inflammation with no specific pathology and no growth of any microorganism. In addition, Leptospira IgM MAC ELISA was done which was positive. Patient was thus confirmed to be having leptospirosis and reactive arthritis as a consequence of it.
Conclusion: The presentation of reactive arthritis secondary to leptospirosis is rare. Leptospirosis can be an etiological fa
Primary Angiosarcoma of Humerus – A Case Report and Literature Review
Authors: Jeyaraman Madhan , Muthu Sathish , Prabhakar Manoj , Jeyaraman Naveen , Agarwal Garima , Jain Rashmi
Published: August 2021

Introduction: Osseous angiosarcoma is a very rare tumor of bone with aggressive behavior, propensity for recurrences, and distant metastasis. The etiology of osseous angiosarcoma is uncertain; however, specific risk factors have been recognized. The diagnosis of angiosarcoma of bone demands multimodality imaging in conjunction with histopathological and vascular marker evaluation to aptly differentiate them from other vascular tumors. Treatment of osseous angiosarcoma remains controversial.
Case Report: A 53-year-old male presented with pain and swelling of the right upper 1/3rd of the arm following heaviness while lifting weight for 3 months. He had a history of significant weight loss and appetite with no history of inciting trauma or irradiation in the past. On examination, a diffuse swelling was noted in the right shoulder and right scapular aspect with varied consistency and ill-defined borders and margins. The skin over the swelling was stretched and shiny with dilated engorged veins over it. The plain radiograph of the right shoulder with humerus revealed a large expansile lytic soft-tissue mass in the right proximal humerus with a wide zone of transition without sclerotic margins. Magnetic resonance imaging showed T1 hypointense, T2/PDFS hyperintense large well-defined expansile lytic lesion with multi-loculated cysts, and multiple blood-fluid levels involving right proximal humerus. The patient underwent an incisional biopsy which exhibited angiosarcoma of the humerus. The patient was treated with six cycles of chemotherapy with a mesna, doxorubicin, ifosfamide, and dacarbazine regimen. The patient was still under follow-up.
Conclusion: Being a rare clinical entity, controversy exists in angiosarcoma of humerus regarding its etiology and recommended management protocols. Histopathology and immunohistochemistry remain the gold standard in differentiating osseous angiosarcoma from other osseous vascular tumors. The treatment protocol has to be standardized to
Ruptured Popliteal Cysts Mimicking Deep Vein Thrombosis in Well-functioning Total Knee Replacements: Report of Two Cases and Review of Literature
Authors: Dhillon Mandeep S. , Vatsya Pulak , Dhatt Sarvdeep S. , Kumar Vishal , Kumar Prasoon
Published: August 2021

Introduction: Implant wear and loosening with eluding metal/polythene debris are commonly implicated in the occurrence of Baker’s cysts in post-operative total knee replacement (TKR) patients, who present with post-operative pain and swelling, mimicking deep venous thrombosis. However, we present two symptomatic cases presenting with ruptured Baker’s cysts post-TKRs, with no evidence of implant loosening or wear.
Cases Report: The 1st patient was a 55-year-old male, who underwent TKR for Grade 4 bilateral knee osteoarthritis and presented with acute onset of pain and swelling over the left popliteal fossa, which progressed to involve the calf. Radiographs showed no sign of infection or loosening, and venous color Doppler and magnetic resonance imaging (MRI) showed a hy-poechoic collection in the intermuscular plane at the upper part of popliteal fossa. Histological examination of the aspirated fluid showed mixed features of cystic fluid and a resolving hematoma. There was complete resolution of the 4 months with rest and graduated physiotherapy. The 2nd patient was a 51-year-old female who developed the cystic swelling 2 years after the surgery, and the ultrasound showed hypoechoic echoes in a Baker’s cyst-like collection. Cytological findings were suggestive of hemorrhagic nature of the aspirate, without any evi-dence of polyethylene debris, and the cultures were sterile. She became asymptomatic over 4 weeks with conservative management; the swelling resolved after 3 months.
Conclusion: Majority of the cases in literature show implant loosening as cause of popliteal cysts after TKRs, however present cases highlight alternative mechanisms, and there are good chances of self-resolution of cysts with conservative treatment in such cases.
Keywords: Knee replacement, Baker’s cyst, deep vein thrombosis, ruptured popliteal cyst.
Rare Case of a Solitary Bone Plasmacytoma of the Proximal Femur Managed with Surgery and Adjuvant Chemotherapy: A Case Report
Authors: Prabhu Rudra M , Keny Swapnil A
Published: August 2021

Introduction: Solitary plasmacytoma of the bone is a rare neoplasm characterized by proliferation of neoplastic plasma cells in the bone in the absence of systemic involvement. We present a managed case of a 64-year-old male with solitary bone plasmacytoma of the right proximal femur, who presented as a pathological subtrochanteric femur fracture.
Case Report: A 64-year-old male presented to our outpatient department with pain in the right hip and restricted range of motion following a trivial trauma. The radiographs showed an osteolytic lesion in the right proximal femur with a right subtrochanteric femur fracture. A magnetic resonance imaging scan revealed a well-defined lesion in the right proximal femur. A 18F-fluorodeoxyglucose positron emission tomography did not show a lesion at any other site suggesting that the lesion was solitary. A serum protein electrophoresis study was normal and the urine was negative for myeloma protein. The patient had a score of 12 as per Mirel’s criteria and hence required operative intervention and fixation. The patient was managed with a thorough mechanical and chemical curettage of the lesion followed by fixation with a proximal femur locking plate and augmentation with fibula and iliac crest bone graft. He was then given a chemotherapy regimen consisting of nine cycles of bortezomib, lenalidomide, and dexamethasone.
Conclusion: Solitary bone plasmacytoma is a rare neoplasm of the bone. Early diagnosis and intervention are required to manage it and prevent its progression to multiple myeloma, which is a more aggressive entity and lies at the other end of the spectrum of plasma cell dyscrasias. Management of this lesion requires an active participation of the hematologist and a holistic approach which includes radiotherapy or surgery with possible adjuvant chemotherapy.
Keywords: Solitary bone plasmacytoma, subtrochanteric femur fracture, multiple myeloma, bortezomib, lenalidomide, dexamethasone.
Atraumatic Posterior Hip Dislocation following Short Femoral Nail for Intertrochanteric Fracture Treated by Dual Mobility System in Total Hip Arthroplasty: A Case Report
Authors: Yoshida Yasuhisa , Yoshida Akira , Takashima Yuto , Fujii Hideto
Published: August 2021

Introduction: Atraumatic hip dislocation after short femoral nail (SFN) fixation for an intertrochanteric fracture is extremely rare.
Case Report: An 84-year-old woman presented with an atraumatic posterior hip dislocation that occurred 8 years after SFN fixation for an intertrochanteric hip fracture. She experienced an acute-onset left hip pain when standing up from a sitting position while bathing at a day care facility. We performed total hip arthroplasty (THA) with a dual mobility system. During the post-operative THA evaluation, the combined anteversion angle was within the optimum range of 57. However, the dislocation recurred after the THA. During the revision THA, a dual mobility system was used to moderately extend the stem neck. Measures were adopted to strain the posterior soft tissues of the hip joint. We speculated that the posterior hip joint capsule ruptured because the support of the posterior hip joint was weak after the intertrochanteric hip fracture. At the final follow-up visit at 6 months after the operation, the hip joint pain had disappeared, and her activities of daily living recovered to almost the same level as her preinjury activities.
Conclusions: We should consider the lack of support of posterior soft tissues as a cause of this atraumatic posterior hip dislocation following intertrochanteric fracture fixation.
Keywords: Atraumatic posterior hip dislocation, post-operative state of intertrochanteric hip fracture, short femoral nail, total hip arthroplasty, dual mobility system.
Rising Trend of “Veil Entanglement Injuries” in Northern Ghana: A Case Series
Authors: Buunaaim Alexis D. B. , Seidu Anwar Sadat , Bukari Mohammed Issah Suglo , Alatiga John Abanga , Tano Kouakou Emile , Yempabe Tolgou
Published: August 2021

Introduction: Veils are thin garments that are worn over the head, wrapped round the neck, and left hanging loosely over the torso up to the thighs. They are also known as scarf or “dupatta.” Veils can get entangled in spokes of motorbikes or in belt-driven machinery resulting in a variety of life-threating injuries.
Case Reports: We report nine major cases of veil entanglement injuries (VEI) that presented to the Orthopedic Unit of Tamale Teaching Hospital from July 10, 2017 to June 12, 2020. All the patients were females with ages ranging from 5-months to 44-year. All the accidents involved either a motorbike or auto rickshaw. Head, neck, and extremity injuries were the most common. Eight out of nine patients had circumferential neck bruise referred to as “veil sign” in this report. One patient died.
Conclusion: The rising trend of VEI is alarming among women in Northern Ghana. We recommend widespread public education and awareness creation. We also recommend modification of traffic regulations by policy makers to avert this avoidable injury.
Keywords: “Dupatta,” long scarf injuries, “Isadora Duncan syndrome,” veil injuries.
Osteochondroma Presenting Clinically with Carpal Tunnel Syndrome in a 12-Year-old Boy
Authors: Kale Sachin Yashwant , Gunjotikar Aditya Rajendra , Sane Rohit Mahesh , Singh Sushmit , Dhar Sanjay B , Patil Raju Laxmanrao
Published: August 2021

Introduction: An exostosis is a benign growth of bone, which when capped with cartilage is called osteochondroma, which can appear as solitary or multiple, mostly affecting the long bones, pelvis, and shoulder region. The prevalence of known solitary exostosis is 1–2% in the general population. They are slow growing lesions with rare malignant transformation. In patients with a solitary exostosis, the chance of developing a chondrosarcoma out of an exostosis is around 1%.
Case Report: A 12-year-old boy presented to our outpatient department with complaints of pain, and swelling at the right wrist since 1 year and tingling numbness on and around palmar aspect of index and middle finger since 6 months. The swelling was of size 3 cm × 2 cm, Tinel’s sign was positive. His blood parameters were normal. X-ray showed exostoses. Magnetic resonance imaging was suggestive of osteochondroma. Nerve conduction study was normal. Excision biopsy confirmed the diagnosis and also relieved all symptoms.
Conclusion: Our case report is unique in its own way as it reminds us that when presented with a case of osteochondroma of the distal radius in children, carpal tunnel syndrome can also occur.
Keywords: Osteochondroma, carpal tunnel syndrome, exostosis.
Nicotinamide effects on the metabolism of human fibroblasts and keratinocytes assessed by quantitative, label-free fluorescence imaging
Authors: Liu Zhiyi , Chiang Chung-Yi , Nip John , Feng Lin , Zhang Yang , Rocha Sheila , Georgakoudi Irene
Published: August 2021

Alterations in metabolism are central to the aging process. Therefore, understanding the subcellular functional and structural changes associated with metabolic aging is critical. Current established methods for exploring cell metabolism either require the use of exogenous agents or are destructive to the tissue or cells. Two-photon excited fluorescence (TPEF) imaging has emerged as a method for monitoring subtle metabolic changes non-invasively. In this study, we use TPEF imaging to acquire high-resolution fluorescence images from two coenzymes, NAD(P)H (reduced form of nicotinamide adenine dinucleotide) and FAD (flavin adenine dinucleotide), within human fibroblasts and keratinocytes in response to B3 (a nicotinamide precursor) supplementation and/or UV irradiation, without addition of exogenous labels. In addition, multi-parametric analysis methods are used to extract functional information of cellular metabolism, including cellular redox state, NAD(P)H fluorescence lifetime, and mitochondrial organization. Our results demonstrate that such optical metabolic assessments can serve as sensitive, label-free, non-destructive reporters of known effects of B3 to maintain and in some cases even enhance the respiratory function of mitochondria, while lowering oxidative damage. Thus, TPEF imaging, supported by highly-quantitative analysis, can serve as a tool to understand aging-dependent metabolic changes as well as the effect of actives on human epidermal and dermal cells.
Optimization of metasurfaces under geometrical uncertainty using statistical learning
Authors: Elsawy Mahmoud M. R. , Binois Mickaël , Duvigneau Régis , Lanteri Stéphane , Genevet Patrice
Published: August 2021

The performance of metasurfaces measured experimentally often discords with expected values from numerical optimization. These discrepancies are attributed to the poor tolerance of metasurface building blocks with respect to fabrication uncertainties and nanoscale imperfections. Quantifying their efficiency drop according to geometry variation are crucial to improve the range of application of this technology. Here, we present a novel optimization methodology to account for the manufacturing errors related to metasurface designs. In this approach, accurate results using probabilistic surrogate models are used to reduce the number of costly numerical simulations. We employ our procedure to optimize the classical beam steering metasurface made of cylindrical nanopillars. Our numerical results yield a design that is twice more robust compared to the deterministic case.
W-band optical modulators using electro-optic polymer waveguides and patch antenna arrays
Authors: Kaji Takahiro , Morohashi Isao , Tominari Yukihiro , Sekine Norihiko , Yamada Toshiki , Otomo Akira
Published: August 2021

In this study, W-band (75–110 GHz) antenna-coupled optical modulators with a cyclo-olefin polymer (COP) lower cladding, an electro-optic (EO) polymer waveguide, and a gap-embedded patch antenna array were fabricated using a transfer and bonding method of a poled EO polymer film. A carrier-to-sideband ratio (CSR) of 56 dB corresponding to an optical phase shift of 3 mrad was obtained under irradiation with 100 GHz electromagnetic waves with a power of 12.8 W/m2. Our devices have the potential to achieve highly efficient wireless–optical signal conversion in radio-over-fiber (RoF) systems.
Transparent and ultra-wideband metamaterial absorber using coupled hexagonal combined elements
Authors: Jiang Hao , Yang Wei , Lei Shiwen , Hu Haoquan , Chen Bo , Bao Yongfang , He Ziyuan
Published: August 2021

Optically transparent microwave absorbers have been widely reported for electromagnetic stealth applications over the past few years, but developing ultra-wideband absorbers with high angular stability remains challenging. In this work, an absorber comprising a double-layer polymethylpentene (TPX) block and indium tin oxide (ITO) films has been designed, fabricated, and measured, respectively. Firstly, an impedance layer with novel coupled hexagonal combined elements is exploited to achieve ultra-wideband absorption. Secondly, to provide the optimal reflection response for high angular incidences, the TPX block with the lower permittivity is initially employed in the compensation and substrate layers. Finally, the experimental results agreed with simulation ones illustrate the excellent performance is concurrently achieved, including a 90% absorption bandwidth within 2.53-8.94 (111.8%), high angular stability (60°), and the high light transmittance (70.7%).
Robust, fast and sensitive near-infrared continuous-filtering Vernier spectrometer
Authors: Lu Chuang , Vieira Francisco Senna , Głuszek Aleksander , Silander Isak , Soboń Grzegorz , Foltynowicz Aleksandra
Published: August 2021

We present a new design of a robust cavity-enhanced frequency comb-based spectrometer operating under the continuous-filtering Vernier principle. The spectrometer is based on a compact femtosecond Er-doped fiber laser, a medium finesse cavity, a diffraction grating, a custom-made moving aperture, and two photodetectors. The new design removes the requirement for high-bandwidth active stabilization present in the previous implementations of the technique, and allows scan rates up to 100 Hz. We demonstrate the spectrometer performance over a wide spectral range by detecting CO2 around 1575 nm (1.7 THz bandwidth and 6 GHz resolution) and CH4 around 1650 nm (2.7 THz bandwidth and 13 GHz resolution). We achieve absorption sensitivity of 5 × 10−9 cm-1 Hz-1/2 at 1575 nm, and 1 × 10−7 cm-1 Hz-1/2 cm-1 at 1650 nm. We discuss the influence of the scanning speed above the adiabatic limit on the amplitude of the absorption signal.
Cross-iteration multi-step optimization strategy for three-dimensional intensity position correction in phase diverse phase retrieval
Authors: Zhao Lei , Yan Hao , Fei Wenhui , Lu Binjie , Hou Jing , Ju Guohao , Wang Kaiwei , Bai Jian
Published: August 2021

Parameters mismatching between the real optical system and phase retrieval model undermines wavefront reconstruction accuracy. The three-dimensional intensity position is corrected in phase retrieval, which is traditionally separated from lateral position correction and axial position correction. In this paper, we propose a three-dimensional intensity position correction method for phase diverse phase retrieval with the cross-iteration nonlinear optimization strategy. The intensity position is optimized via the coarse optimization method at first, then the intensity position is cross-optimized in the iterative wavefront reconstruction process with the exact optimization method. The analytic gradients about the three-dimensional intensity position are derived. The cross-iteration optimization strategy avoids the interference between the incomplete position correction and wavefront reconstruction during the iterative process. The accuracy and robustness of the proposed method are verified both numerically and experimentally. The proposed method achieves robust and accurate intensity position correction and wavefront reconstruction, which is available for wavefront measurement and phase imaging.
Switchable metasurface for nearly perfect reflection, transmission, and absorption using PIN diodes
Authors: Song Xinyun , Yang Weixu , Qu Kai , Bai Xudong , Chen Ke , Feng Yijun , Zhu Weiren
Published: August 2021

Active metasurfaces with dynamically switchable functionalities are highly in demands in various practical applications. In this paper, we experimentally present an active metasurface based on PIN diodes which can realize nearly perfect reflection, transmission and absorption in a single design. Such switchable functionalities are accomplished by controlling the PIN diodes integrated in both layers of the metasurface. A transmission line model is employed to further investigate the underlying mechanism of the metasurface. This proposal is confirmed by numerical simulations and experiments. As a novel metasurface with multiple switchable functionalities, our design may find some practical applications such as smart radomes.
Improved joint subcarrier and power allocation to enhance the throughputs and user fairness in indoor OFDM-NOMA VLC systems
Authors: Wang Geyang , Shao Yingjie , Chen Lian-Kuan , Zhao Jian
Published: August 2021

Orthogonal frequency division multiplexing non-orthogonal multiple access (OFDM-NOMA) is a promising multi-user access scheme in indoor visible light communication (VLC) systems. In this paper, we propose three novel joint subcarrier and power allocation algorithms in OFDM-NOMA-VLC to improve the throughputs and/or user fairness. These three proposed algorithms address the requirements in fairness-throughput-balanced (FTB), fairness-first (FF), and throughput-first (TF) scenarios, respectively. All of them improve the objective function in the previous joint allocation algorithm and ensure the fairness of users in terms of their overall throughput, rather than that in every subcarrier that is tight and redundant. The designs using the proposed algorithms also exhibit reduced peak-to-average power ratios (PAPRs) and so the average signal power can be better used to further enhance the throughput when the system is limited by the signal peak power. Simulations verify that the proposed algorithms are superior to the previous joint subcarrier and power allocation algorithm as well as the conventional fixed power allocation (FPA) and gain ratio power allocation (GRPA) algorithms. The performance improvement of the proposed algorithms is particularly greater for a larger number of multiplexed users per subcarrier or a larger number of OFDM subcarriers, under which the PAPRs of designs using conventional algorithms are higher. When the total user number, the number of the multiplexed users per subcarrier, and the number of subcarriers are 5, 2, and 16, respectively, the throughputs of the three proposed algorithms are 62.17%, 53.35%, and 67.25% higher than the conventional joint allocation algorithm, while the user fairness is improved by 4.64%, 7.87%, and degraded by 20.71%, respectively. Therefore, the three proposed algorithms can address the requirements in FTB, FF, and TF scenarios, respectively.
Experimental demonstration of a broadband optoelectronic chaos system based on highly nonlinear configuration of IQ modulator
Authors: Luo Hanwen , Cheng Mengfan , Huang Chuanming , Ye Bolin , Shao Weidong , Deng Lei , Yang Qi , Zhang Minming , Liu Deming
Published: August 2021

We experimentally investigated a novel broadband optoelectronic chaos generation scheme. The proposed system is achieved by adopting the highly nonlinear operation of an electro-optical exclusive-NOR (XNOR) logic gate and two delayed feedback loops that refer to the Boolean chaos model. The XNOR gate is established by a commercial use inphase and quadrature-phase (IQ) modulator that works at a specific bias point. The resulting power spectrum of the broadband chaos signal extends from DC to 29.1 GHz (10 dB bandwidth), and the probability density distribution is Gaussian distribution like. Owing to the strong nonlinearity of XNOR operation, the conditions to enter the chaos region are more relaxed compared to traditional optoelectronic oscillator (OEO) chaos systems, and the time delay signature (TDS) of the feedback loop is also suppressed. Moreover, to further enhance the performance of the generated chaos signal, we injected the optoelectronic chaotic signal into a semiconductor laser. Experimental results indicate that after the cascade optical injection, the bandwidth of the output chaos signal is extended to 38.4 GHz and the TDS is completely concealed; meanwhile, a perfect Gaussian distribution can be obtained.
Mid-infrared intersubband absorption in strain-balanced non-polar (In)AlGaN/InGaN multi-quantum wells
Authors: Nguyen Trang , Dzuba Brandon , Cao Yang , Senichev Alexander , Diaz Rosa E. , Manfra Michael J. , Malis Oana
Published: August 2021

Mid-infrared intersubband transitions in strain-balanced m-plane (In)AlxGa1-xN/In0.16Ga0.84N (0.19≤x≤0.3) multi-quantum wells are reported for the first time in the range of 3.4–5.1 µm (244–360 meV). Direct and attenuated total-reflection infrared absorption measurements are interpreted using structural information revealed by high-resolution x-ray diffraction and transmission electron microanalysis. The experimental intersubband energies are better reproduced by calculations using the local-density approximation than the Hartree-Fock approximation for the exchange-correlation correction. The effect of charge density, quantum well width, and barrier alloy composition on the intersubband transition energy is also investigated to evaluate the potential of this material for practical device applications.