bluuebunny/crossref_metadata_2025 huggingface dataset:
A systematic review of symptomatic hamartomas of the jejunum and ileum
Authors: Farkas N , Conroy M , Baig M
Published: May 2023

Introduction

Gastrointestinal hamartomas are rarely encountered benign growths made of an abnormal mixture of tissues normally found in the body where the growth occurs. Most hamartomas are asymptomatic and diagnosed incidentally. Evidence regarding symptomatic hamartomas of the jejunum and ileum is limited and restricted to anecdotal case reports. We aim to provide a contemporary overview to clarify various aspects linked to symptomatic hamartomas, helping aide management and clinical decision-making.

Methods

The search terms ‘small bowel’, ‘small intestine’, ‘jejunum’ and ‘ileum’ were combined with ‘hamartoma’. Embase, Medline, PubMed searches and Google Scholar hand-searches were conducted. All English language papers from 1 January 2000 to 1 June 2020 were included.

Results

In total 39 cases were reviewed: 29 adults and 10 paediatric (0–16 years). Presenting symptoms included abdominal pain (87%), vomiting (56%), gastrointestinal bleeding (20.5%) and weight loss (5%); 36 of 39 cases (92%) presented as emergencies. Diagnostic investigations included: abdominal x-ray (49%), endoscopy (38%), computed tomography (56%), magnetic resonance imaging (5%), contrast study (15%) and video capsule endoscopy (5%). Initial management strategy was either open (30) or laparoscopic (7) surgery or endoscopy (2). All cases required surgery for definitive management. Twenty-five cases recorded hamartoma size, and mean maximum diameter was 3.56cm (1.2–8cm) with stricturing in seven cases. Nine of the 39 cases were associated with hamartomatous syndromes. Two mortalities were recorded.

Conclusions

This is the first published review addressing symptomatic hamartomas of the jejunum and ileum. New data relating to demographic cohort, symptom profile, investigations, management strategies, and morbidity and mortality provide greater insight to those encountering this challenging clinical finding in the future.
Severe duodenal ulcer behaves like gastroduodenal intussusception
Authors: Hung TH , Huang JW
Published: May 2023

Intestinal intussusception is uncommon in adults. As a retroperitoneal structure, gastroduodenal intussusception is extremely rare. The leading cause of intussusception is reported to be a tumour, either benign or malignant. The case presented may be the first of gastroduodenal intussusception resulting from severe peptic ulcer. A 64-year-old man was admitted with epigastralgia, appetite loss and melena for 1 week. He had history of peptic ulcer and reflux esophagitis for 9 years, caused by Helicobacter pylori infection; eradication therapy had been performed 5 years previously. This time, an abdominal computed tomography scan showed duodenogastric intussusception and gastric outlet obstruction. Preoperative biopsy failed for complete obstruction; thus, the patient underwent Whipple procedure for complete resection under impression of malignancy. The postoperative course was uneventful. Pathological findings for the specimen showed gastric and duodenal ulcer. Progressive peptic ulcer after eradication therapy is rarely seen, and eradication therapy is used widely to treat H. pylori infection. The eradication rate is extremely high in Taiwan for lower first-line antibiotic as clarithromycin resistance is low due to a policy restricting antimicrobial usage. Early eradication therapy is highly recommended for patients with H. pylori infection. We emphasise the importance of regular follow-up for the non-significant correlation of severity of gastric ulcer with clinical symptoms. When ulceration progresses or non-invasive treatments fail early surgical interventions should be applied to these anatomic alterations.
Few UK vascular centres offer a fully NICE-compliant supervised exercise programme: a national audit
Authors: Haque A
Published: May 2023

Introduction

To determine the current (pre-COVID-19) provision of supervised exercise training (SET) for patients with peripheral arterial disease (PAD) in UK Vascular Centres.

Methods

Hospital Trusts delivering vascular care to patients with PAD were identified from the National Vascular Registry and asked to complete an online questionnaire on their provisions for SET. If a centre offered SET, they were asked questions to determine whether the programme was compliant with NICE guidelines and the difficulties they faced delivering the service. If centres did not offer SET, they were asked what obstacles prevented them implement SET.

Results

Of the 78 UK vascular centres, 59 (76%) responded and were included in the audit. Of these, 27 (46%) were able to offer SET but only 21 (36%) could offer it to all their patients with PAD. Only four (6.8%) offered SET that was fully compliant with current NICE guidelines. Reasons identified included insufficient funding, lack of resource and poor patient compliance.

Conclusions

The benefits of SET are well established yet the availability of the service in the UK is poor. The reasons for this are readily identified but have not yet been overcome. Research on novel methods of delivering supervised exercise that mitigates existing barriers, such as home exercise with remote monitoring, should be prioritised to facilitate optimal management for our patients with PAD.
Can one-step nucleic acid amplification assay predict four or more positive axillary lymph node involvement in breast cancer patients: a single-centre retrospective study
Authors: Kenny R , Wong G , Gould L , Odofin O , Bowyer R , Sotheran W
Published: May 2023

Background

One-step nucleic acid amplification (OSNA) assay is a proven, accurate, intraoperative method for the detection of lymph node (LN) metastases. The aim of this study was to assess if the total tumour load (TTL) as calculated by OSNA could be used to predict N2 stage disease, ie ≥4 LN containing metastases, in invasive breast cancer patients.

Methods

Between 2011 and 2019 at St Richard’s Hospital, Chichester, all macro-metastasis-positive OSNA cases for invasive breast cancer were retrospectively reviewed. The association between clinicopathological variables and ≥4 LNs containing metastases was analysed using regression analysis.

Results

In total, 134 patients with positive sentinel lymph node (SLN) on OSNA undergoing axillary node clearance were analysed, 53% of whom had no further positive LN, 25% had ≥4 lymph nodes positive. TTL was calculated as the aggregate of cytokeratin-19 mRNA copy count of all SLN tissue analysed via OSNA. TTL ≥1.1×105copies/μl and lymphovascular invasion (LVI) were both significant predictors of N2 stage disease on both univariate (TTL p=0.04, LVI p=0.005) and multivariate (TTL p=0.008, LVI p=0.039) regression analysis.

Conclusion

Our findings show that SLN TTL via intraoperative OSNA assay can predict four or more positive axillary LN involvement in invasive breast cancer. This is important in that it may be used intraoperatively by surgeons to decide on whether to proceed with a full axillary node clearance in order to stage the axilla. Further research is required to shape future guidance.
Patient characteristics and refusal to participate in a head and neck cancer intervention trial: experience of two tertiary UK head and neck cancer centres
Authors: Rogers SN , Lowe D , Highet V , Dukanovic G , Lowies C , Thomas S , Kanatas A
Published: May 2023

Introduction

Randomised clinical trials are an essential component for robust clinical evaluation. They are expensive to deliver but can fail to achieve the required outcomes. This paper reports details of trial recruitment in a head and neck Patient Concerns Inventory intervention trial from two UK head and neck tertiary centres.

Materials and methods

Data were collected for a pragmatic cluster preference randomised control trial with 15 consultants recruiting patients treated with curative intent after a diagnosis of head and neck cancer (all sites, disease stages, treatments). Ethical approval was given to report on those not recruited by the following characteristics: trial site, trial arm, age, sex, tumour site, overall stage, index of multiple deprivation quintile, timeframe.

Results

There were 368 patients approached who remained eligible and 80 (22%) declined to participate. Logistic regression suggested that age group (p = 0.008) and index of multiple deprivation quintile group (p = 0.003) were independent predictors of refusal.

Conclusions

Although recruitment to the trial was very good, it raised the issue of lower recruitment in the more deprived older group and lower social economic strata. Innovative ways need to be explored to facilitate the ‘hard to reach’ group contributing to, and benefiting from, clinical trials.
The effect of strap muscle transection on voice and swallowing changes after thyroidectomy in patients without laryngeal nerve injury
Authors: Aygun N , Celayir MF , Isgor A , Uludag M
Published: May 2023

Introduction

Voice and swallowing symptoms are frequently reported after thyroidectomy even without laryngeal nerve injury. We aimed to evaluate the effect of strap muscle transection on voice and swallowing outcome after thyroidectomy.

Methods

Group 1 (G1) consisted of 17 patients who had their strap muscles transected during thyroidectomy and group 2 (G2) consisted of 17 patients who had their strap muscles preserved during thyroidectomy. None of the patients had laryngeal nerve injury. Voice impairment scores (VIS) and swallowing impairment scores (SIS) were obtained preoperatively and at 1 week and 1, 3 and 6 months postoperatively. Pre- and postoperative vocal cord examinations were performed for all patients. The external branch of the superior laryngeal nerve (EBSLN) was evaluated by intraoperative cricothyroid muscle electromyography.

Results

There was no significant difference in VIS and SIS between the two groups. At postoperative week 1, the VIS and SIS for each group were above preoperative values (G1: p = 0.005 and p = 0.035; G2: p = 0.031, p = 0.346, for VIS and SIS respectively). The VIS and SIS scores at 6 months postoperatively were significantly lower than those of the first week postoperatively (G1: p = 0.04 and p = 0.001; G2: p = 0.022 and p = 0.034 respectively) and similar to preoperative values (G1: p = 0.924 and p = 0.086; G2: p = 0.822 and p = 0.187 respectively).

Conclusion

Although voice and swallowing complaints increased in the early postoperative period even without recurrent laryngeal nerve and EBSLN injuries, these symptoms are not related with the strap muscle transection.
Idiopathic granulomatous mastitis: experience at a New York hospital
Authors: Bhattarai P , Srinivasan A , Valenzuela CD , Sulzbach C , Wallack MK , Mariadason JG
Published: May 2023

Introduction

Idiopathic granulomatous mastitis (IGM) often mimics breast cancer. Presentation includes pain, palpable mass, suppuration or suspicious imaging. Widely reported in Asia and the Middle East, IGM is diagnosed after excluding specific granulomatous mastitis (SGM). Aetiology remains unknown. Lactation, prolactinaemia, ethnicity, autoimmune disease and Corynebacteria are associated. Treatment is controversial and the prevalence rising. Surgery and non-operative treatments including antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), steroids, methotrexate and observation have advocates.

Methods

A retrospective chart review of 63 patients with IGM from 2008 to 2018 was undertaken focusing on birthplace, age, clinical presentation, wound cultures, imaging, treatments and outcomes.

Results

Sixty-one of 63 patients were Hispanic; 53 were Mexican-born women aged 23–46. Clinical presentation included pain, painful mass, painless mass, suppuration and abnormal imaging. Some 31/61 ultrasound examinations and 17/33 mammograms were deemed Breast Imaging Reporting and Data System (BI-RADS) score 4 or 5. Management included antibiotics (43), incision and drainage (24), NSAIDs (29), steroids (8), lumpectomy (18) and observation (12). Some 12/20 patients with painless masses resolved with observation, 3 received NSAIDs, 2 received steroids and 3 underwent lumpectomies. Antibiotics resolved 8/43 cases, 5 needed incision and drainage, 26 received NSAIDs, 6 received steroids and 5 underwent lumpectomies. Nineteen patients had indolent disease or recurrence.

Conclusions

Excluding malignancy is critical, treatment challenging and recurrence common in IGM. A preponderance of patients were Mexican-born, similar to other reports from the USA. Over 50% of IGM cases had suspicious BI-RADS scores. Best management remains a challenge and ranges from observation to lumpectomy.
A survey of UK and Irish surgeons’ attitudes, behaviours and barriers to change for environmental sustainability
Authors: Harris H , Bhutta MF , Rizan C
Published: May 2023

Introduction

Surgery is a major contributor to the large environmental impact of healthcare, demanding urgent attention. To date there are no data on the attitudes and behaviours of surgeons towards climate change, or perceived barriers towards sustainable practice.

Methods

We invited surgeons and surgical trainees in the UK and Ireland to participate in an online survey (developed in accordance with the CHERRIES checklist) conducted between June and November 2020 and disseminated via the Royal College of Surgeons of England, Edinburgh and Ireland, the Association of Surgeons in Training and through local communication.

Results

We received 130 responses, across 14 surgical specialties. The majority of respondents (122/130; 94%) were concerned about the threat of climate change. Most respondents had instigated more sustainable practices in their personal lives (113/130; 87%) and, to a lesser extent, at work (73/130; 56%). Surgeons were willing to make changes to their clinical practice (107/130; 82%), but the main perceived barrier to improving sustainability was a lack of leadership (92/130; 70%). Surgeons welcomed greater leadership and guidance from national bodies (118/130; 91%) and more monitoring and regulation (113/130; 87%).

Conclusions

The surgeons who responded to our survey are concerned about climate change and willing to engage in efforts to transition to more sustainable practice, but would welcome greater support, guidance and leadership.
Assessing secondary care oral surgery referral complexities and casemix
Authors: Patel Roshni , Gerrard Greg
Published: May 2023

Can we increase the success of referrals for complex cases through improving existing guidance?
ZnO Production from EAF Solid Waste Using Hydrothermal Methods via Oxalate Precipitation
Authors: Nulhakim Lukman , Prasetyo Imam , Rozana Monna , Astuti Widi
Published: May 2023

Electric Arc Furnace (EAF) waste contains 50-60% Zn. EAF waste synthesis has the potential to produce ZnO, which can be used in a variety of applications. The hydrothermal method is used in the synthesis, with time variations of 3 and 6 hours and temperature variations of 120 °C, 150 °C and 200 °C using precipitating reagents in the form of sodium hydroxide (NaOH) and oxalic acid (C2H2O4). UV-Vis spectrophotometer characterization result shows the absorbance value at 365 nm, which is the absorbance characteristic of ZnO material. The result of increasing the Zn element was revealed by XRF characterization. The XRD characterization revealed zinc oxalate dehydrates. This result depicts the hydrothermal with the oxalic acid solvent used to produce zinc oxalate dehydration at various temperatures and time variations.
Preliminary Study of NFRP-Confined Concrete for Enhancing Compressive Strength
Authors: Saidi Taufiq , Hasan Muttaqin , Amalia Zahra
Published: May 2023

Earthquake that occurred within a period of several years may be caused reinforced concrete column fails to maintain its performance. Reinforcement methods to improve the quality of concrete in resisting earthquake loads are needed. Strengthening the column with external restraints is expected to increase the strength of the concrete. The use of synthetic Fiber Reinforced Polymer (FRP) as a composite material for external restraint on structures is one of the materials that has been widely used for strengthening concrete structures. Considering the environmental impact, natural FRP materials have been developing nowadays. One of the natural fibers that have been researched and used as a composite material for Natural Fiber Reinforced Polymer (NFRP) is abaca fiber. This research aims to find the contribution of abaca fiber in increasing the compressive strength of confined concrete as a preliminary study. In this study, the test was carried out by applying a compressive load to concrete specimens reinforced with NFRP restraints. The NFRP was investigated with variations in the number of NFRP layers. The results showed that NFRP-confined concrete has a higher compressive strength of 34.73% than the controlled specimen
Off-axis three-mirror freeform systems design based on improved W-W differential equations
Authors: Chen Sike , Wei Yangjie , Sun YiWei , Li BaoTing , Zhao Ji
Published: May 2023

Design of an off-axis system using the Wassermann–Wolf (W-W) differential equations can effectively eliminate the spherical aberration and coma problem; however, it is complicated and time consuming to calculate the discrete point coordinates on the freeform mirror surfaces due to multiple numbers of reference system transformation in the design process. This paper presents an improved W-W-differential-equations-based design method for off-axis three-mirror freeform systems. First, to reduce the number of coordinate transformations, a geometric relationship between different optical rays in an off-axis system is established using the distance between the central points of adjacent mirrors. Second, a three-dimensional rotation matrix is used to associate the optical paths passing through adjacent mirrors in different reference coordinate systems, and new simplified W-W differential equations based on the ray vectors are constructed. The experimental results show that our method can easily and effectively design off-axis three-mirror freeform systems with different parameters and structures, and the designed systems have good imaging quality.
Optical trapping of gold microparticles using linearly polarized, centrally obstructed Gaussian beams
Authors: Yun Xue , Liang Yansheng , He Minru , Zhao Tianyu , Wang Shaowei , Lei Ming
Published: May 2023

Metallic microparticles larger than the illumination wavelength are commonly considered poor optical trapping candidates due to their high extinction coefficient. This paper presents a numerical and experimental study on the three-dimensional (3D) trapping of gold microparticles using a centrally obstructed Gaussian beam based on the T-matrix method. The range of particle size for stable optical trapping is determined. For the trapping numerical aperture of 1.32 and illumination wavelength of 1.064 µm, numerical analysis proves that 3D trapping of gold microparticles with a radius bigger than 1.0 µm can be readily achieved. By imprinting a digital lens to the spatial light modulator, we slightly defocus the centrally obstructed Gaussian beam to shift the trapping location to the focal plane for clear observation. Experimental results demonstrate stable trapping of gold microparticles with a radius greater than 1.4 µm at high-power illumination, agreeing well with the theoretical predictions. The presented work should be of interest to the community applying metallic microparticles to relevant research.
Reduction formula for cross-spectral purity of nonstationary light fields
Authors: Laatikainen Jyrki , Luo Meilan , Halder Atri , Koivurova Matias , Setälä Tero , Turunen Jari , Friberg Ari T.
Published: May 2023

We examine cross-spectral purity of random, nonstationary (pulsed), scalar light fields with arbitrary spectral bandwidth. In particular, we derive a reduction formula in terms of time-integrated coherence functions, which ensures cross-spectral purity of interfering fields having identical normalized spectra. We further introduce fields that are cross-spectrally pure in either a global or local sense. Our analysis is based on an ideal field superposition realizable with all-reflective wavefront-shearing interferometers. Such devices avoid certain problems related to Young’s interferometer, which is the framework customarily employed in assessing cross-spectral purity. We show that any partially coherent beam can be transformed into a locally cross-spectrally pure beam whose cross-spectral density is specular. On the other hand, lack of space–frequency (and space–time) coupling ensures cross-spectral purity in the global sense, i.e., across an entire transverse plane, regardless of the spectral bandwidth or the temporal shape of the pulses.
Fresnel reflections in inverse double freeform lens design
Authors: van Roosmalen A. H. , Anthonissen M. J. H. , Ijzerman W. L. , ten Thije Boonkkamp J. H. M.
Published: May 2023

In this paper we present a method for designing a double freeform lens that includes the effect of Fresnel reflections on the output intensity. We elaborate this method for the case of a point source and a far-field target. A new expression for the transmittance through a double freeform lens is derived, and we adapt a least-squares algorithm to account for this transmittance. A test case based on street lighting is used to show that our adaptation improves the accuracy of the algorithm and that it is possible to minimize Fresnel losses with this new method to design efficient lenses.
Observation of the “invisible” pulsation of soliton molecules in a bidirectional ultrafast fiber laser
Authors: Wang Qingbo , Wang Pan , Xu Qiaoqiao , Shi Zhifeng , He Jiangyong , Wang Zhi , Liu Yan-ge
Published: May 2023

A novel optical soliton dynamics phenomenon, called “invisible” pulsation, has gradually attracted extensive interest in recent years, which can only be identified effectively with the help of real-time spectroscopy technique, i.e., dispersive Fourier transformation (DFT). In this paper, based on a new bidirectional passively mode-locked fiber laser (MLFL), the “invisible” pulsation dynamics of soliton molecules (SMs) is systematically studied. It is indicated that the spectral center intensity, pulse peak power and relative phase of SMs are periodically changed during the “invisible” pulsation, while the temporal separation inside the SMs is constant. The degree of spectral distortion is positively correlated with the pulse peak power, which verifies that self-phase modulation (SPM) is the inducement of spectral distortion. Finally, the universality of the SMs “invisible” pulsation is further experimentally verified. We believe our work is not only conducive to the development of compact and reliable bidirectional ultrafast light sources, but also of great significance to enrich the study of nonlinear dynamics.
On the performance stability of MCF-based SDM system affected by inter-core crosstalk fluctuation
Authors: Zhao Xuesong , Bo Tianwai , Tan Zhongwei , Dong Yi
Published: May 2023

The inter-core crosstalk (IC-XT) of multi-core fiber (MCF) limits the capacity of space division multiplexing system (SDM) fundamentally. We develop a closed-form expression of the magnitude of IC-XT for various types of signals, which can well explain the mechanism of different fluctuation behaviors of the real-time short-term average crosstalk (STAXT) and bit error ratio (BER) for the optical signals with and without strong optical carrier. The experimental verifications with the real-time measurement of the BER and outage probability in a 7 × 10-Gb/s SDM system agree well with the proposed theory and confirm that the unmodulated optical carrier plays a substantial role in fluctuation of BER. The range of fluctuation can be reduced by 3 orders of magnitude for the optical signal without optical carrier. We also investigate the effect of IC-XT in a long-haul transmission system based on a recirculating 7-core fiber loop and develop a frequency-domain IC-XT measurement technique. Longer transmission distance is shown to have a narrower BER fluctuation range, since IC-XT is no longer the only dominant factor on transmission performance.
170-W Nd:YAG InnoSlab laser at 1319 nm
Authors: Meng Xiangrui , Zhang Xuguang , Chen Xiaoming , Luo Xingwang , Ye Junzhi , Zhang Lei , Gao Qingsong , Lu Baole
Published: May 2023

In this paper, a continuous-wave Nd:YAG InnoSlab laser at 1319 nm with high output power and high beam quality is demonstrated. The maximum output power of 170 W at 1319-nm single wavelength is obtained with an optical-to-optical efficiency of 15.3% from absorbed pump power to laser output and the corresponding slope efficiency of 26.7%. The beam quality factors of M2 are 1.54 and 1.78 in the horizontal and vertical directions, respectively. To the best of our knowledge, this is the first report on Nd:YAG 1319-nm InnoSlab lasers with such high output power and good beam quality.
Low-complexity optimized detection with cluster assisting for C-band 64-Gb/s OOK transmission over 100-km SSMF
Authors: Xie Fei , Liu Shuangyue , Huang Xiaoqian , Cui Han , Tang Du , Qiao Yaojun
Published: May 2023

In this paper, a low-complexity optimized detection scheme consisting of a post filter with weight sharing (PF-WS) and cluster-assisted log-maximum a posteriori estimation (CA-Log-MAP) is proposed. Besides, a modified equal-width discrete (MEWD) clustering algorithm is proposed to eliminate the training process during clustering. After channel equalization, optimized detection schemes improve performance by suppressing the in-band noise raised by the equalizers. The proposed optimized detection scheme was experimentally performed in a C-band 64-Gb/s on-off keying (OOK) transmission system over 100-km standard single-mode fiber (SSMF) transmission. Compared with the optimized detection scheme with the lowest complexity, the proposed method saves 69.23% required number of real-valued multiplications per symbol (RNRM) at 7% hard-decision forward error correction (HD-FEC). In addition, when the detection performance reaches saturation, the proposed CA-Log-MAP with MEWD saves 82.93% RNRM. Compared with the classic k-means clustering algorithm, the proposed MEWD has the same performance without a training process. To the best of our knowledge, this is the first time clustering algorithms have been applied to optimize decision schemes.
Enhancement of blue and ultraviolet components in PCF-based supercontinuum generation through inter-modal dispersive-wave radiation
Authors: Yang X. T. , Luo Z. Z. , Huang J. P. , Sun W. Y. , Zheng Y. , Yin R. C. , Dong H. , Yu H. H. , Pang M. , Jiang X.
Published: May 2023

Broadband supercontinuum (SC) light sources generated through nonlinear effects in solid-core photonic crystal fibers (PCFs) have been widely used in spectroscopy, metrology, and microscopy, leading to great application successes. The short-wavelength extension of such SC sources, a longstanding challenge, has been the subject of intensive study over the past two decades. However, the exact mechanism of blue and ultraviolet light generation, especially for some resonance spectral peaks in the short-wavelength regime, is not yet fully understood. Here, we demonstrate that the effect of inter-modal dispersive-wave radiation, which results from phase matching between pump pulses at the fundamental optical mode and packets of linear waves at some higher-order modes (HOMs) propagating in the PCF core, might be one of the critical mechanisms that can result in some resonance spectral components with wavelengths much shorter than that of the pump light. We observed in an experiment that several spectral peaks resided in the blue and ultraviolet regimes of the SC spectrum, whose central wavelengths can be tuned by varying the PCF-core diameter. These experimental results can be interpreted well using the inter-modal phase-matching theory, providing some useful insights into the SC generation process.
Multidimensional synthetic frequency lattice in the dynamically modulated waveguides
Authors: Liu Zhuoxiong , Zheng Lingzhi , Qin Chengzhi , Wang Bing , Lu Peixiang
Published: May 2023

Here we propose an effective method to construct a higher-dimensional synthetic frequency lattice with an optical waveguide under dynamic modulation. By applying the traveling-wave modulation of refractive index modulation with two different frequencies that are not mutually commensurable, a two-dimensional frequency lattice could be formed. The Bloch oscillations (BOs) in the frequency lattice is demonstrated by introducing a wave vector mismatch of the modulation. We show that the BOs are reversible only as the amounts of wave vector mismatch in orthogonal directions are mutually commensurable. Finally, by employing an array of waveguides with each under traveling-wave modulation, a 3D frequency lattice is formed and its topological effect of one-way frequency conversion is revealed. The study offers a versatile platform for exploring higher-dimensional physics in concise optical systems and may find great application in optical frequency manipulations.
On the electroluminescence overshoot of quantum-dot light-emitting diodes
Authors: Yu Rongmei , Yin Furong , Pu Chunying , Zhou Dawei , Ji Wenyu
Published: May 2023

The charge-carrier dynamics is a fundamental question in quantum-dot light-emitting diodes (QLEDs), determining the electroluminescence (EL) properties of the devices. By means of a hole-confined QLED design, the distribution and storage/residing of the charge carriers in the devices are deciphered by the transient electroluminescence (TrEL) spectroscopic technology. It is demonstrated that the holes stored in the quantum dots (QDs) are responsible for the EL overshoot during the rising edge of the TrEL response. Moreover, the earlier electroluminescence turn-on behavior is observed due to the holes residing in the hole-confined structure. The hole storage effect should be attributed to the ultralow hole mobility of QD films and large barrier for hole escape from the cores of the QDs. Our findings provide a deep understanding of the charge transport and storage at the most critical interface between QDs and hole-transport layer, where the excitons are formed.
Ultrahigh-linearity dual-drive scheme using a single silicon modulator
Authors: Yue Hengsong , Chen Kaizhong , Chu Tao
Published: May 2023

Here, a high-linearity dual-drive scheme using a single silicon dual-drive Mach–Zehnder modulator is presented. The bias voltages and RF amplitudes of the two driving arms are adjusted such that the nonlinearity of the transfer function of the Mach–Zehnder interferometer cancels out the nonlinear response of the arms. Using the proposed scheme, the spurious-free dynamic range of the third-order intermodulation distortion is 123.4 dB Hz6/7, which is believed to be a record-breaking value for silicon modulators. In comparison, the result obtained using a conventional single-drive scheme is 102.6 dB·Hz2/3. The proposed scheme could simplify the design of modulators and promote high-performance microwave photonic links.
Beyond pathogenesis: Detecting the full spectrum of ecological interactions in the virosphere
Authors: Jurburg Stephanie D. , Hom Erik F. Y. , Chatzinotas Antonis
Published: May 2023

The public perception of viruses has historically been negative. We are now at a stage where the development of tools to study viruses is at an all-time high, but society’s perception of viruses is at an all-time low. The literature regarding viral interactions has been skewed towards negative (i.e., pathogenic) symbioses, whereas viral mutualisms remain relatively underexplored. Viral interactions with their hosts are complex and some non-pathogenic viruses could have potential benefits to society. However, viral research is seldom designed to identify viral mutualists, a gap that merits considering new experimental designs. Determining whether antagonisms, mutualisms, and commensalisms are equally common ecological strategies requires more balanced research efforts that characterize the full spectrum of viral interactions.
Self-assembly coupled to liquid-liquid phase separation
Authors: Hagan Michael F. , Mohajerani Farzaneh
Published: May 2023

Liquid condensate droplets with distinct compositions of proteins and nucleic acids are widespread in biological cells. While it is known that such droplets, or compartments, can regulate irreversible protein aggregation, their effect on reversible self-assembly remains largely unexplored. In this article, we use kinetic theory and solution thermodynamics to investigate the effect of liquid-liquid phase separation on the reversible self-assembly of structures with well-defined sizes and architectures. We find that, when assembling subunits preferentially partition into liquid compartments, robustness against kinetic traps and maximum achievable assembly rates can be significantly increased. In particular, both the range of solution conditions leading to productive assembly and the corresponding assembly rates can increase by orders of magnitude. We analyze the rate equation predictions using simple scaling estimates to identify effects of liquid-liquid phase separation as a function of relevant control parameters. These results may elucidate self-assembly processes that underlie normal cellular functions or pathogenesis, and suggest strategies for designing efficient bottom-up assembly for nanomaterials applications.
Targeting operational regimes of interest in recurrent neural networks
Authors: Ekelmans Pierre , Kraynyukova Nataliya , Tchumatchenko Tatjana
Published: May 2023

Neural computations emerge from local recurrent neural circuits or computational units such as cortical columns that comprise hundreds to a few thousand neurons. Continuous progress in connectomics, electrophysiology, and calcium imaging require tractable spiking network models that can consistently incorporate new information about the network structure and reproduce the recorded neural activity features. However, for spiking networks, it is challenging to predict which connectivity configurations and neural properties can generate fundamental operational states and specific experimentally reported nonlinear cortical computations. Theoretical descriptions for the computational state of cortical spiking circuits are diverse, including the balanced state where excitatory and inhibitory inputs balance almost perfectly or the inhibition stabilized state (ISN) where the excitatory part of the circuit is unstable. It remains an open question whether these states can co-exist with experimentally reported nonlinear computations and whether they can be recovered in biologically realistic implementations of spiking networks. Here, we show how to identify spiking network connectivity patterns underlying diverse nonlinear computations such as XOR, bistability, inhibitory stabilization, supersaturation, and persistent activity. We establish a mapping between the stabilized supralinear network (SSN) and spiking activity which allows us to pinpoint the location in parameter space where these activity regimes occur. Notably, we find that biologically-sized spiking networks can have irregular asynchronous activity that does not require strong excitation-inhibition balance or large feedforward input and we show that the dynamic firing rate trajectories in spiking networks can be precisely targeted without error-driven training algorithms.
Knowledge-guided data mining on the standardized architecture of NRPS: Subtypes, novel motifs, and sequence entanglements
Authors: He Ruolin , Zhang Jinyu , Shao Yuanzhe , Gu Shaohua , Song Chen , Qian Long , Yin Wen-Bing , Li Zhiyuan
Published: May 2023

Non-ribosomal peptide synthetase (NRPS) is a diverse family of biosynthetic enzymes for the assembly of bioactive peptides. Despite advances in microbial sequencing, the lack of a consistent standard for annotating NRPS domains and modules has made data-driven discoveries challenging. To address this, we introduced a standardized architecture for NRPS, by using known conserved motifs to partition typical domains. This motif-and-intermotif standardization allowed for systematic evaluations of sequence properties from a large number of NRPS pathways, resulting in the most comprehensive cross-kingdom C domain subtype classifications to date, as well as the discovery and experimental validation of novel conserved motifs with functional significance. Furthermore, our coevolution analysis revealed important barriers associated with re-engineering NRPSs and uncovered the entanglement between phylogeny and substrate specificity in NRPS sequences. Our findings provide a comprehensive and statistically insightful analysis of NRPS sequences, opening avenues for future data-driven discoveries.
Understanding children’s experiences of self-wetting in humanitarian contexts: An evaluation of the Story Book methodology
Authors: Rosato-Scott Claire , Alam Mahbub-Ul , Evans Barbara E. , Rose Joanne , Wozei Eleanor , Barrington Dani J.
Published: May 2023

Little is known about how children in humanitarian contexts experience self-wetting. Children can wet themselves due to having the medical condition of urinary incontinence (the involuntary leakage of urine), or due to them not wanting to or not being able to use the toilet facilities available (social or functional incontinence). Self-wetting is a global public health challenge: the physical health of children can suffer; they can miss out on educational and social opportunities; they may face increased protection risks; and the emotional effect on daily life can be significantly negative. The Story Book methodology was developed to facilitate conversations with children aged five to eleven in humanitarian contexts (specifically refugee settlements in Adjumani District, Uganda; and refugee camps in Cox’s Bazar, Bangladesh) about self-wetting to understand how humanitarian professionals can best meet the needs of children that wet themselves. This paper has evaluated how far the Story Book methodology meets the specific requirements of conducting research a) in a humanitarian context; b) with young children; and c) on a personal and highly sensitive topic. Data has been used from Story Book sessions held with children in Adjumani District and Cox’s Bazar, and from semi-structured interviews held with adults known to have participated in the planning and/or facilitation of the sessions. The evaluation found that although the Story Book methodology provided deep insights into how children in humanitarian contexts experience self-wetting, it was not always implemented as designed; it is not practical to implement in humanitarian settings; and it was not acceptable to all participants and facilitators as a research tool. Changes have been recommended to improve the methodology as a research tool to better understand how children experience personal health issues, but even with such changes the methodology will remain better suited to non-humanitarian contexts.
Across atoms to crossing continents: Application of similarity measures to biological location data
Authors: Schuhmann Fabian , Ryvkin Leonie , McLaren James D. , Gerhards Luca , Solov’yov Ilia A.
Published: May 2023

Biological processes involve movements across all measurable scales. Similarity measures can be applied to compare and analyze these movements but differ in how differences in movement are aggregated across space and time. The present study reviews frequently-used similarity measures, such as the Hausdorff distance, Fréchet distance, Dynamic Time Warping, and Longest Common Subsequence, jointly with several measures less used in biological applications (Wasserstein distance, weak Fréchet distance, and Kullback-Leibler divergence), and provides computational tools for each of them that may be used in computational biology. We illustrate the use of the selected similarity measures in diagnosing differences within two extremely contrasting sets of biological data, which, remarkably, may both be relevant for magnetic field perception by migratory birds. Specifically, we assess and discuss cryptochrome protein conformational dynamics and extreme migratory trajectories of songbirds between Alaska and Africa. We highlight how similarity measures contrast regarding computational complexity and discuss those which can be useful in noise elimination or, conversely, are sensitive to spatiotemporal scales.
Socioeconomic inequalities in employees’ health-enhancing physical activity: Evidence from the SHAHWAR cohort study in Iran
Authors: Khoramrooz Maryam , Zare Fariba , Sadeghian Farideh , Dadgari Ali , Chaman Reza , Mirrezaie Seyed Mohammad
Published: May 2023

Background

Increasing level of physical activity (PA) among working population is of particular importance, because of the high return of investment on employees’ PA. This study was aimed to investigate socioeconomic inequalities in Health-Enhancing Physical Activity (HEPA) among employees of a Medical Sciences University in Iran.

Methods

Data were extracted from the SHAHWAR Cohort study in Iran. Concentration index (C) and Wagstaff decomposition techniques were applied to determine socioeconomic inequality in the study outcomes and its contributors, respectively.

Results

Nearly half of the university employees (44.6%) had poor HEPA, and employees with high socioeconomic status (SES) suffered more from it (C = 0.109; 95% CI: 0.075, 0.143). Also, we found while poor work-related PA (C = 0.175; 95% CI: 0.142, 0.209) and poor transport-related PA (C = 0.081, 95% CI: 0.047, 0.115) were more concentrated among high-SES employees, low-SES employees more affected by the poor PA at leisure time (C = -0.180; 95% CI: -0.213, -0.146). Shift working, and having higher SES and subjective social status were the main factors that positively contributed to the measured inequality in employees’ poor HEPA by 33%, 31.7%, and 29%, respectively, whereas, having a married life had a negative contribution of -39.1%. The measured inequality in poor leisure-time PA was mainly attributable to SES, having a married life, urban residency, and female gender by 58.1%, 32.5%, 28.5%, and -32.6%, respectively. SES, urban residency, shift working, and female gender, with the contributions of 42%, 33.5%, 21.6%, and -17.3%, respectively, were the main contributors of poor work-related PA inequality. Urban residency, having a married life, SES, and subjective social status mainly contributed to the inequality of poor transport-related PA by 82.9%, -58.7%, 36.3%, and 33.5%, respectively, followed by using a personal car (12.3%) and female gender (11.3%).

Conclusions

To reduce the measured inequalities in employees’ PA, workplace health promotion programs should aim to educate and support male, urban resident, high-SES, high-social-class, and non-shift work employees to increase their PA at workplace, and female, married, rural resident, and low-SES employees to increase their leisure-time PA. Active transportation can be promoted among female, married, urban resident, high-SES, and high-social-class employees and those use a personal car.
The value of leadership in small enterprises from their employees’ perspective
Authors: Turaeva Gavkhar
Published: May 2023

A vezetés elmélete és gyakorlata alaposan tanulmányozott téma, de a vezetők és követőik közötti kapcsolatok és helyzetek komplexitása továbbra is foglalkoztatja a kutatókat. Jelen kutatás a szakirodalomban meglévő hiányt kívánja kielégíteni azáltal, hogy kvalitatív megközelítéssel azonosítja a független kis éttermek tulajdonosai számára a sikeres vezetővé váláshoz szükséges ideális tulajdonságokat, az étterem alkalmazottainak véleményét kikérve. A kisvállalkozásokat vezetők gondolatainak és tapasztalatainak vizsgálatára, a vezetés fontosságának feltárására a kutatás kvalitatív módszertant alkalmaz. Az adatok egy tizenkét alkalmazottat foglalkoztató kis indiai étteremből és annak két fiókjából kerültek feldolgozásra interjúk segítségével. Az interjúk két külön fókuszcsoportban készültek. Az esettanulmány célja az volt, hogy a résztvevők saját szavaikon keresztül értelmezzék és tudatosítsák tapasztalataikat. A tanulmány megállapításai a kisvállalkozások, különösen az éttermek vezetésének számos fontos tulajdonságát tárta fel, mint például a tisztelet, az együttérzés, a hatékony kommunikáció, a tapasztalat és a jólszervezettség.
Трансформация культуры доверия в России
Authors: Веселов Юрий Витальевич , Скворцов Николай Генрихович
Published: May 2023

В статье рассматриваются процессы формирования и развития культуры доверия в России. Основной исследовательский вопрос — почему в России уровень доверия относительно низкий? Для ответа на него авторы разбирают понятие культуры доверия и ключевые социологические концепции трансформации доверия (Ф. Фукуямы, Э. Гидденса, Н. Лумана, П. Штомпки); объясняют логику формирования доверия в России начала ХХ века; показывают преобразование традиционного доверия, основанного на партикуляризированном доверии внутри крестьянских сообществ, в современное, основанное на доверии генерализированном, институциональном и ролевом. Авторы выявляют причины формирования специфической «культуры недоверия» в 1930-е годы в советском обществе и показывают постепенный процесс накопления «капитала доверия» в послевоенный период. Падение уровня доверия в 1990-е годы связано с «травмой перемен», но начавшееся в 2000-х годах укрепление доверия не имело продолжения. Причины этого множественные, главные из них связаны с ростом социального неравенства (поскольку доверие и справедливость существуют только вместе) и неэффективной работой общественных институтов. Современное преобразование культуры доверия связано с начавшейся цифровой революцией, на наших глазах происходит формирование новой цифровой культуры доверия в социальных сетях, в использовании интернета для дистанционной работы и покупок товаров и услуг. Для анализа культуры доверия авторы провели эмпирическое исследование (телефонный опрос жителей Санкт-Петербурга (N = 1 032), интернет-опрос (N = 505) и 45 глубинных интервью), результаты которого обобщаются в данной статье.
Благодарность. Статья подготовлена при финансовой поддержке РФФИ, грант 20-011-00155 А.
Эффекты периода, возраста и когорты в динамике рождаемости россиян 1990-2021 гг.
Authors: Вакуленко Елена Сергеевна
Published: May 2023

В работе оценивается влияние эффектов возраста, периода и когорты на динамику рождаемости в России. Используются APC (age-period-cohort) модели на основе годовых макроданных о числе рожденных детей с привязкой к возрасту матери в 1990-2021 гг. Применяется ряд методов для решения проблемы идентификации обозначенных эффектов. Наиболее адекватные результаты получены с помощью подходов Intrinsic Estimator (IE) и прокси-переменных.
Результаты исследования показали, что возрастной эффект имеет обратную U-форму, где пик приходится на 21-24-летних матерей. Для анализа эффектов периода наиболее подходящей прокси-переменной, характеризующей экономическую флуктуацию в рассматриваемый период, оказалась цена на нефть. Корреляция между полученными оценками периода и суммарным коэффициентом рождаемости составила 0,66, что говорит о значимой связи рождаемости с происходящими каждый год событиями при контроле на эффекты возраста и когорты. При этом наиболее выраженная роль периода наблюдается в те годы, когда она усиливается когортным влиянием, как это произошло после ввода федеральной программы материнского капитала в 2007 г. Тем не менее, несмотря на положительное влияние периода, с 2014 г. мы наблюдаем снижение рождаемости в России, которое в большей степени объясняется когортными и возрастными эффектами.
Благодарность. Автор благодарит коллектив исследовательской рабочей группы по экономико-математическому моделированию экономических процессов на факультете экономических наук НИУ ВШЭ за ценные комментарии и замечания и лично Е.С. Митрофанову за обсуждения результатов на начальной стадии исследования.
Исследование выполнено за счет гранта Российского научного фонда № 22-28-00952 «Исследование динамики рождаемости в России: эконометрический подход» https://rscf.ru/project/22-28-00952/.