bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization of convolutional neural networks for background suppression in the PandaX-III experiment
Authors: Xia Shangning , Huang Suizhi , Xu Kexin , Li Tao , Chen Xun , Han Ke , Wang Shaobo
Published: September 2023

The tracks recorded by a gaseous detector provide a possibility for charged particle identification. For searching the neutrinoless double beta decay events of 136Xe in the PandaX-III experiment, we optimized the convolutional neural network based on the Monte Carlo simulation data to improve the signal-background discrimination power. EfficientNet is chosen as the baseline model and the optimization is performed by tuning the hyperparameters. In particular, the maximum discrimination power is achieved by optimizing the channel number of the top convolutional layer. In comparison with our previous work, the significance of discrimination has been improved by ∼70%.
Geometric and electronic structures of medium-sized boron clusters doped with plutonium
Authors: Zuo Jingning , Zhang Lili , Chen Bole , He Kaihua , Dai Wei , Ding Kewei , Lu Cheng
Published: September 2023

Doping metal heteroatoms is an effective strategy to regulate the geometric and electronic structure of boron based nanoclusters. However, the exploration of the ground state structures of metal-boron-based nanoclusters is still a challenge duo to the complexity of the bonding interactions between heterogeneous atoms and boron cluster and the number of isomers on the potential energy surface increases exponentially with cluster size. Here, we use the CALYPSO cluster structural search method in combination with density functional theory calculations to study the geometries and electronic properties of anionic boron clusters doped with plutonium (PuB

n

−

, n = 10–20). Our results show that the medium-sized PuB

14

−

cluster exhibits excellent stability with highest occupied molecular orbital–lowest unoccupied molecular orbital energy gap of 2.30 eV. The remarkable stability of the anionic PuB

14

−

cluster is due to the robust interactions between the Pu metal and the B14 skeleton, along with the strong covalent interactions between the B atoms. These findings enrich the geometric structure database of metal doped clusters and provide valuable insights for the future synthesis of boron based nanomaterials.
Multi-head spatio-temporal attention based parallel GRU architecture: a novel multi-sensor fusion method for mechanical fault diagnosis
Authors: Li Yaozong , Luo Xiong , Xie Yuhao , Zhao Wenbing
Published: September 2023

The sensor signals with multiple measuring points and data types not only bring sufficient information, but also put forward more stringent requirements for multi-sensor fusion efficiency and fault feature extraction capability. The redundancy and conflicts in the information of multi-sensor signals often hinder the accurate extraction of crucial fault features. To address this problem, our study proposes an intelligent mechanical fault diagnosis method, which is based on a multi-head spatio-temporal attention mechanism and parallel gated recurrent units (GRUs) architecture. This method utilizes multiple attention heads to model the correlation information in spatial and temporal dimensions, and employs a parallel GRU network for targeted feature extraction. Finally, it combines local features from different attention heads to achieve flexible scheduling of various spatio-temporal attention modes. This novel application and fusion approach of multi-head attention enables accurate identification of the spatio-temporal value differences in the collected multi-sensor signals from multiple perspectives. Experimental results on multiple mechanical fault datasets show that the proposed method performs well in multi-sensor signals based mechanical fault diagnosis tasks and can maintain effectiveness under small samples and imbalanced data conditions.
A hybrid framework for robust dynamic 3D point clouds removal
Authors: Zhu Hongwei , Zhang Guobao , Liang Quncong , Ye Zhiqi
Published: September 2023

When robot creates a map, dynamic objects can change the space and render the map unusable for navigation. Additionally, the vertical resolution of a VLP-16 LiDAR may be insufficient, making dynamic point removal challenging. To address these challenges, we propose a novel method for dynamic point detection and removal consisting of four components. Firstly, we introduce a multi-resolution heightmap to enhance the efficiency and precision of dynamic point recognition by segmenting ground points. Secondly, we address the issue of limited vertical resolution by fusing multiple scans to simulate additional scan lines and leveraging a multi-resolution range image for precise dynamic point elimination. Thirdly, we apply clustering and principal component analysis-based techniques to compute eigenvectors, facilitating the correction of misclassified static points. Lastly, we propose the utilization of a three-dimensional bounding box strategy to reinforce the monitoring of small static clusters with elevated probabilities of misclassification. These four components complement each other and are executed sequentially. We evaluated our method for both dynamic point removal and ground segmentation on the KITTI dataset and real-world environments. The results demonstrate that our method outperforms baseline methods and generates clean maps.
Enabling real-time detection of photocatalytic reactions by a re-useable micro-reactor
Authors: Hochfilzer Degenhart , Aletsee Clara , Krempl Kevin , Pedersen Thomas , Krabbe Alexander , Tschurl Martin , Hansen Ole , Vesborg Peter C K , Kibsgaard Jakob , Heiz Ulrich , Chorkendorff Ib
Published: September 2023

We present a highly sensitive and versatile Si-based μ-reactor for photocatalytic experiments. The μ-reactor can be operated in front side (through a borosilicate window) as well as backside (through the catalyst support) illumination. The μ-reactor is sealed by compressing the Si-based microchip, a parafilm gasket and the supported catalyst by four screws. This design allows for fast and reliable assembly of the μ-reactor and the microchip is re-usable for several independent experiments, making the presented μ-reactor ideal for catalyst screening studies. We analyze volatile reactants on-line by connecting the μ-reactor to a mass-spectrometer. The limiting capillary of the μ-reactor allows for nearly 100% collection efficiency (i.e. every produced molecule will be collected) by limiting the gas flow to the mass-spectrometer—enabling highly sensitive measurements and an absolute calibration. Finally, the small height of the reactor volume results in very fast response times, which make the reactor suitable for studies of transient activity phenomena—including catalyst activation and deactivation. We demonstrate these capabilities of the μ-reactor by performing CO oxidation experiments on a TiO2 thin film with subsequent calibration of the chip. Based on a mathematical model of the μ-reactor we additionally present a method for determining the residence time, the reaction volume and the working distance.
Singular component decomposition and its application in rolling bearing fault diagnosis
Authors: Yang Miaorui , Xu Yonggang , Zhang Kun , Zhang Xiangfeng
Published: September 2023

In the rolling bearing fault diagnosis based on vibration signal, the feature information always exists in the specific sideband of the signal. Singular value, as a mathematical quantity can represent the characteristic information of data, provides the theoretical support for extracting fault information from signals. Based on this, this paper proposes a new method called Singular Component Decomposition (SCD). The signal is divided into components by the signal spectrum trend. Through linear transformation of Hankel matrix constructed by each component, the corresponding singular values are calculated. Combined with the amplitude filtering characteristic and the time domain negative entropy index, the effective singular values are screened out. The reconstructed components retain complete fault information for fault diagnosis of rolling bearings. The simulation and experimental results show that the SCD can extract the effective information to the maximum extent to realize the fault diagnosis of the signal.
Deep transfer learning rolling bearing fault diagnosis method based on convolutional neural network feature fusion
Authors: Yu Di , Fu Haiyue , Song Yanchen , Xie Wenjian , Xie Zhijie
Published: September 2023

Current deep-learning methods are often based on significantly large quantities of labeled fault data for supervised training. In practice, it is difficult to obtain samples of rolling bearing failures. In this paper, a transfer learning-based feature fusion convolutional neural network approach for bearing fault diagnosis is proposed. Specifically, the raw vibration signal features and the corresponding time-frequency image features of the input data are extracted by a one-dimensional convolutional neural network and a pre-trained ConvNeXt, respectively, and connected by a feature fusion strategy. Then, the fine-tuning method based on transfer learning can effectively reduce the reliance on labeled samples in the target domain. A wide convolution kernel is introduced in the time-domain signal feature extraction to increase the receptive field, which is combined with the channel attention mechanism to further optimize the feature quality. Finally, two common bearing datasets are utilized for fault diagnosis experiments. The experimental results show that the proposed model achieves an average accuracy of more than 98.63% in both cross-working conditions and cross-device diagnosis tasks. Meanwhile, anti-noise experiments and ablation experiments further validate the accuracy and robustness of the proposed method.
Enhancement and quenching of plasmon-enhanced spectroscopy of single molecule confined in metallic nanoparticle dimers
Authors: Pei Huan , Zhao Jiaxin , Peng Weifeng , Dai Qiyuan , Wei Yong
Published: September 2023

We present a theoretical analysis of plasmon-enhanced fluorescence (PEF) and Raman scattering (PERS) spectroscopy of a single molecule confined in the laser-irradiated metallic nanoparticles (NPs) dimer, focusing on the origin of the spectral enhancement and quenching effects. The theoretical method of D-parameters has been used to calculate the dimer distance-dependent nonlocal dielectric effect in Ag and Au NPs. Meanwhile, other damping rates and electric field enhancements are quantitatively computed by finite element method. Moreover, PEF and PERS spectra of rhodamine 6G are obtained within the density-functional theory. Our calculated results show that the PERS mainly depend on the excitation and emission field enhancements, and thus it occurs at the narrower dimer gap due to the stronger localized plasmon coupling. The PEF is related to fluorescence rate caused by the competition between excitation electric field and quantum efficiency, and the increase of former may enhance the fluorescence intensity while the lower latter lead to reduce the intensity as decreasing the dimer distance. The contribution of nonlocal dielectric effect can significantly reduce the quantum efficiency at smaller distance so that it overcomes the excitation field enhancement, leading to the fluorescence quenching for Au NPs dimer. Furthermore, by optimizing the dimer distance and NPs size, the maximum PERS and PEF cross sections reach 10−14 and 10−15 under 2.45 eV laser excitation for Ag NPs dimer, and 10−18 for Au NPs. Our study finely explains the experiment results showed either fluorescence enhancement or quenching with the change of molecule-NPs distance, and better guidance for optimizing the experiments.
Black silicon spacing effect on bactericidal efficacy against gram-positive bacteria
Authors: Kayes Md Imrul , Zarei Mehdi , Feng Fanbo , Leu Paul W
Published: September 2023

The morphology of regular and uniform arrays of black silicon structures was evaluated for bactericidal efficacy against gram-positive, non-motile Staphylococcus
epidermidis (S.
epidermidis). In this study, uniform and regular arrays of black silicon structures were fabricated using nanosphere lithography and deep reactive ion etching. The effects of nanomorphology on bacterial killing were systematically evaluated using silicon nanostructures with pitches ranging from 300 to 1400 nm pitch on spherical cocci approximately 500 to 1000 nm in diameter. Our results show that nanostructure morphology factors such as height and roughness do not directly determine bactericidal efficacy. Instead, the spacing between nanostructures plays a crucial role in determining how bacteria are stretched and lysed. Nanostructures with smaller pitches are more effective at killing bacteria, and an 82 ± 3% enhancement in bactericidal efficacy was observed for 300 nm pitch nanoneedles surface compared to the flat control substrates.
Interplay of spin–orbit and exchange interaction in a ferromagnet/heavy-metal hybrid system: Ni on W(110)
Authors: J Grenz Pascal , Krüger Peter , Donath Markus
Published: September 2023

In a combined experimental and theoretical study, we investigate the interplay of spin–orbit interaction (SOI) and exchange interaction (XI) in the electronic structure of ultrathin Ni films on W(110). Using spin- and angle-resolved inverse photoemission, we observe that the size of the spin splitting of Ni-related exchange-split states differs for opposite magnetization directions. A quenched spin splitting for one of the magnetization directions reveals a contribution of SOI on an equal footing with XI. Using density-functional theory calculations, we explore the underlying mechanisms responsible for the experimentally observed coupling of SOI and XI. We find that a hybridization between adsorbate and substrate states, along with a high probability density of the respective states at the heavy W nuclei, cause the strong influence of SOI on the Ni-related exchange-split states.
Real-space renormalization-group treatment of quadratic chains
Authors: Citrin D S
Published: September 2023

We have recently proposed a one-dimensional nonperiodic chain with lattice positions at 02
d, 12
d, 22
d, ... with length d a constant. The spectrum is singular-continuous, and for weak potential, the states are all extended apart from a trivial set of localized states. In this study, we obtain the exact extended-state spectrum of the quadratic chain in a nearest-neighbor tight-binding model where the quadratic modulation is in the onsite matrix elements. Then, a real-space renormalization-group method (RSRG) is used by decimation to reduce the transfer matrix for the chain into self-similar matrix products. The RSRG decimation scheme is used here to organize the calculation and facilitate numerical computation. The extended-state spectrum appears as minibands broken by numerous gaps. Previous work on quadratic chains shows that the structure factor is singular-continuous and given by a dense set of states with wavevectors with scaling exponent γ(k) = 2 as in periodic and quasi-periodic chains. The origin of extended states in this nonperiodic lattice appears to arise from a type of mechanism not yet identified in deterministic nonperiodic lattices, and is based on a hidden symmetry giving rise to an energy-dependent translational invariance of the transfer matrix.
A wide measurement range plasmonic refractive index sensor based on side-polished photonic crystal fiber
Authors: Zhang Sa , Wu Biao , Gao Zhigang , Chen Hailiang
Published: September 2023

A wide measurement range plasmonic refractive index (RI) sensor based on side-polished photonic crystal fiber (PCF) was proposed and studied in this paper. A composite film containing an Au layer and a TiO2 layer was coated on the polished surface of PCF to excite and modulate the surface plasmon resonance (SPR) effect. The sensing characteristics were analyzed using the finite element method (FEM). Numerical results showed that the sensing performances were significantly improved through introducing the unique optoelectronic material of TiO2 film. The designed RI sensor showed an ultra-wide measurement range of 1.20–1.38 with a highest sensitivity of 14600 nm RIU−1. The best resolution (R) and figure of merit (FOM) reached 6.85 × 10−6 RIU and 224.62 RIU−1, respectively. The designed side-polished PCF which is coated with an optimized TiO2/Au composite membranes has a promising performance in the field of RI sensing requiring high sensitivity and wide range monitoring.
On QSPR study of energies and thermodynamic aspects of anti-malaria medicines
Authors: Huang Lei , Mahboob Abid , Siddiqui Muhammad Kamran , Imran Muhammad , Waheed Rasheed Muhammad , Waqas Muhammad
Published: September 2023

Malaria is a serious infection that is transmitted by mosquitoes. It is transmitted when a person is bitten by an infected Anopheles mosquito. It effects the red blood cells and also the spleen and liver size increase as the infection deepens. Anemia or jaundice could also results from malaria. In extreme circumstances, it can target the brain and cause neurological issues. 3.3 billion peoples, or over half of the world’s population, are in danger from malaria. The frequency, signs, and causes of malaria, as well as the possible treatments, are all carefully discussed in this article. Nine medications that are used to treat malaria are employed in the quantitative structure-property relationship (QSPR) analysis. For the molecular structures of the drugs under consideration in this study, which are shown as molecular graphs, five energies are determined. There is also a statistical modeling for physio-chemical attributes with energies.
Preliminary experimental research on RF coupling efficiency of CRAFT NNBI prototype ion source
Authors: Wang Na , Liu Zhimin , Wei Jianglong , Xie Yahong , Yang Yuwen , Jiang Caichao , Gu Yuming , Su Guojian , Peng Xufeng , Xie Junwei , Xie Yuanlai
Published: September 2023

A radio frequency inductively coupled plasma source was chose as the prototype ion source for CRFAT NNBI system. The RF coupling efficiency of this negative ion(H−) source is researched by experiment. The effect of the RF ion source’s multi-cusp confinement magnet on the RF coupling efficiency is focused on. It is found that the RF ion source, equipped with a linear type cusp magnet array on the expansion chamber walls, exhibits a higher efficiency of 2% to 6.6% compared to the checkerboard type. Furthermore, the RF coupling efficiency improves by approximately 9% when a confinement magnet is used, as opposed to not having one. The variations in bias voltage have no impact on the RF coupling efficiency. Nonetheless, variations in the magnetic field within the driver region caused by changes in the PG current induce an impact on the plasma in that region. When the PG current was raised from 800 A to 2500 A, it led to a minor reduction in RF coupling efficiency of approximately 2%.
Calcium storage in multivesicular endo-lysosome
Authors: Scott Cameron C , Wasnik Vaibhav , Nunes-Hassler Paula , Demaurex Nicolas , Kruse Karsten , Gruenberg Jean
Published: September 2023

It is now established that endo-lysosomes, also referred to as late endosomes, serve as intracellular calcium store, in addition to the endoplasmic reticulum. While abundant calcium-binding proteins provide the latter compartment with its calcium storage capacity, essentially nothing is known about the mechanism responsible for calcium storage in endo-lysosomes. In this paper, we propose that the structural organization of endo-lysosomal membranes drives the calcium storage capacity of the compartment. Indeed, endo-lysosomes exhibit a characteristic multivesicular ultrastructure, with intralumenal membranes providing a large amount of additional bilayer surface. We used a theoretical approach to investigate the calcium storage capacity of endosomes, using known calcium binding affinities for bilayers and morphological data on endo-lysosome membrane organization. Finally, we tested our predictions experimentally after Sorting Nexin 3 depletion to decrease the intralumenal membrane content. We conclude that the major negatively-charge lipids and proteins of endo-lysosomes serve as calcium-binding molecules in the acidic calcium stores of mammalian cells, while the large surface area of intralumenal membranes provide the necessary storage capacity.
Effects of atmospheric aerosols on heat stress over South Asia
Authors: Ajay Parottil , Nair Vijayakumar S , Babu S Suresh , Das Chiranjit , K H Usha
Published: September 2023

The recent trend in global mean temperature is expected to increase the frequency, duration, and intensity of heat waves and heat stress all around the world, especially over the Indian subcontinent. To investigate the plausible mechanisms and implications of meteorological feedback of aerosol forcing on heat stress over South Asia, simulations using a regional climate model (RegCM4) coupled with aerosols were carried out from 2015 to 2019. Generally, extreme heat days are observed mainly over the central and western Indo-Gangetic plains (IGPs) during May. The two heat-humidity indices, wet-bulb temperature (WBT) and heat index (HI), showed moderate effects due to aerosol forcing despite the high aerosol loading during the pre-monsoon. The inclusion of aerosols leads to surface cooling (a reduction in maximum surface temperature), with the highest impact over western India (WI) and the IGP. However, this surface cooling due to aerosols is compensated by an increase in near-surface relative humidity (RH), leading to an increase in WBT and HI. This compensating effect of RH on WBT and HI is greater in WI than that in eastern India. Regional heterogeneity in aerosol-induced changes in heat stress has a strong dependence on land-atmosphere interactions. This study clearly shows that aerosol-induced changes in RH play a decisive role in the assessment of heat stress, which answers the link between the prevalence of high heat stress conditions despite high aerosol loading (surface cooling) over the Indian region.
The social contract: consent of those governed
Authors: Zack Naomi
Published: September 2023

This chapter focuses on the concept of a social contract, which was accepted as the core of modern conceptions of democratic national governments. Social contract theory’s driving insight is that legitimate government requires the consent of those governed. Moreover, early social contract theory offered new ideas about the best form and origins of governments. Thomas Hobbes, John Locke, and Jean-Jacques Rousseau contributed to the modern theory of the social contract based on the fiction of the state of nature to justify forms of government relevant to their historical circumstances and the interests that they represented.
New democracies and new conceptions of democracy
Authors: Zack Naomi
Published: September 2023

This chapter explains the influence of World War II on 20th-century thought about democracy and new forms of activism. The Allies imposed new democratic political structures on the governments of Germany, Italy, and Japan to prevent another world war. However, the war had followed the rise of fascism, which was considered to be the antithesis of democracy. New ideas came from Hannah Arendt, John Rawls, Amartya Sen, and Karl Popper. Internal developments of democracy often resulted from popular movements with charismatic leaders like Mohandas Gandhi, Martin Luther King, and Nelson Mandela. The chapter also suggests how natural emergencies can provide opportunities to expand democracy, but upheavals, like a man-made war, may increase vulnerability to undemocratic regressions.
The future of democracy: threats and resilience
Authors: Zack Naomi
Published: September 2023

This chapter considers the threats to, and resilience of, democracy, by looking into history and current events. Democracy has become an internationally recognized ideal for society, as well as for government. However, the goal of social equality has been met by backlash against gains for minorities, presenting new problems for progressives. According to the political theorist Arthur Bentley, external forces or biological differences cannot account for the social disadvantages suffered by some groups. Therefore, democratic humanitarian policies are an important element of political morality. The chapter addresses such problems in democracy as internal politics, natural disasters, climate change, pandemics, conspiracy theories, and undemocratic populism.
Spectres in the prison garden
Authors: Boehmer Elleke
Published: September 2023

This chapter explores Nelson Mandela’s prison years in Robben Island Maximum Security Prison, Pollsmoor and Victor Verster. It mentions how Mandela was incarcerated for a longer period than his political mentors Mahatma Gandhi and Jawaharlal Nehru. The predominant spectral qualities of life on Robben Island range from the cooperation between prisoners and warders, the brutal regime of everyday existence, and the transformative aspects of incarceration. Gardening offered Mandela a practical correlative to his visions of change. Even though Mandela entered the prison as a hot-headed opinionated young leader, he left prison life as a reflective, disciplined person able to force a consensus and yet to draw humanity out of another by sheer conviction and persistence.
How does film music work?
Authors: Kalinak Kathryn
Published: September 2023

Film music can be music in its own right, but when it is “film music” it is defined by its function within a cinematic field of reference. “How does film music work?” introduces some of the basic ways in which film music can be meaningful, in terms of both its constitution as music and its function as a component of filmic narrative. Musical concepts examined include tonality, melody, harmony, rhythm, tempo, dynamics, timbre, instrumentation, and form. Film music concepts examined include parallelism and counterpoint as well as mutual interdependence. Examples in this chapter are drawn from a variety of eras and global practices and include Psycho, Beauty and the Beast, Monsoon Wedding, The Good, the Bad, and the Ugly, The Power of the Dog, The Shape of Water, and Lars von Trier’s Europa trilogy.
The U.S. Supreme Court
Authors: Greenhouse Linda
Published: September 2023

The U.S. Supreme Court: A Very Short Introduction draws on the Court’s history and its written and unwritten rules to show how it operates in the twenty-first century. Today’s Supreme Court, housed in a majestic building on Capitol Hill, bears little resemblance to the institution launched by the Framers of the Constitution and was originally seen as the weakest of the three branches of government. Over the next 200 years, the Court put the independence the Framers gave it to use and now largely defines itself, exercising so much power over how Americans live that some have begun to question whether the Court has gone too far. How do cases reach the Supreme Court? What features have other courts around the world taken from the Supreme Court, and what have they left?
The Court at work (1)
Authors: Greenhouse Linda
Published: September 2023

A very small percentage of all cases decided by the country’s judicial system reach the Supreme Court. “The Court at work (1)” explains that even if a case meets all the criteria, the justices are not likely to accept it. The Court has navigated debates about the separation of powers and conflicting approaches to interpretations of the statutes. The growth of the administrative state means that the Court is now more often tasked with determining whether administrative agencies are carrying out their duties correctly. What do cases and controversies mean to the Supreme Court? Why are these terms important, and how have the Court’s interpretations of them changed over time?
The justices
Authors: Greenhouse Linda
Published: September 2023

There are no formal requirements for becoming a Supreme Court justice. “The justices” notes that the job is theoretically open to anyone who can be nominated by the president and confirmed by a majority vote. The current Supreme Court consists of nine justices. The first membership was entirely Protestant, and there were no women until 1981. Now, there are four women, and all but two of the justices were raised in the Catholic Church. The modern court lacks diversity of professional backgrounds; all but one of the justices were formerly federal appellate judges. Some appointments, both historical and recent, have been controversial. It is not unheard of for a justice’s ideology to drift after his or her appointment, in some cases amounting to considerable changes in outlook during that justice’s time in the Court.
Alcohol Consumption and Antihypertensive Treatment Effect in Male Patients With Hypertension
Authors: Ye Xiao-Fei , Wang Wen-Yuan-Yue , Wang Xin-Yu , Huang Qi-Fang , Li Yan , Wang Ji-Guang
Published: September 2023

BACKGROUND

Alcohol consumption is a proven risk factor of hypertension. In the present analysis, we investigated the use of antihypertensive medications and blood pressure control in male alcohol drinkers and non-drinkers with hypertension (systolic/diastolic blood pressure 160–199/100–119 mm Hg).

METHODS

The study participants were patients enrolled in a 12-week therapeutic study and treated with the irbesartan/hydrochlorothiazide combination 150/12.5 mg once daily, with the possible up-titration to 300/12.5 mg/day and 300/25 mg/day at 4 and 8 weeks of follow-up, respectively, for blood pressure control of <140/90 mm Hg or <130/80 mm Hg in patients with diabetes mellitus. Alcohol consumption was classified as non-drinkers and drinkers.

RESULTS

The 68 alcohol drinkers and 168 non-drinkers had similar systolic/diastolic blood pressure at baseline (160.8 ± 12.1/99.8 ± 8.6 vs. 161.8 ± 11.0/99.2 ± 8.6, P ≥ 0.55) and other characteristics except for current smoking (80.9% vs. 47.6%, P < 0.0001). In patients who completed the 12-week follow-up (n = 215), the use of higher dosages of antihypertensive drugs was similar at 4 weeks of follow-up in drinkers and non-drinkers (10.6% vs. 12.4%, P = 0.70), but increased to a significantly higher proportion in drinkers than non-drinkers at 12 weeks of follow-up (54.7% vs. 36.6%, P = 0.01). The control rate of hypertension tended to be lower in alcohol drinkers, compared with non-drinkers, at 4 weeks of follow-up (45.6% vs. 58.9%, P = 0.06), but became similar at 12 weeks of follow-up (51.5% vs. 54.8%, P = 0.65).

CONCLUSION

Alcohol drinkers compared with non-drinkers required a higher dosage of antihypertensive drug treatment to achieve similar blood pressure control.

CLINICAL TRIAL REGISTRY NUMBER

NCT00670566 at www.clinicaltrials.gov.
Testing the function of a colour pattern polymorphism in a lizard
Authors: Matthews Genevieve , Chapple David G
Published: September 2023

Trait polymorphisms can vary across different contexts of selection and be maintained through trade-offs between these contexts. For example, colour polymorphic variants may represent alternative strategies optimizing crypsis or thermoregulation in different populations. Here we use visual modelling to test the conspicuousness of different colour pattern morphs in males and females of an Australian lizard, Lampropholis delicata, to predators and conspecifics. We further assess differences in reflectance, microhabitat selection, and mate preference to determine the functional role of the polymorphism and explain its variable distribution across latitude and the sexes. Plain morphs are more conspicuous than striped morphs in both bird and lizard visual models, suggesting predation selection, and habitat structure varies among sex-morph types, but we find no difference in microhabitat selection or mate preference based on colour. We suggest that a combination of spatially varying selection, habitat preference, and context-specific behaviour may be necessary to explain spatial patterns of colour morph frequencies.
Assessing the genetic risk of nodular melanoma using a candidate gene approach
Authors: Stark Mitchell S , Sturm Richard A , Pan Yan , Smit Darren J , Kommajosyula Varsha , Lee Katie J , Jagirdar Kasturee , McLean Catriona , Duffy David L , Soyer H Peter , Mar Victoria J
Published: September 2023

Background

Nodular melanoma (NM) is a challenge to diagnose early due to its rapid growth and more atypical clinical presentation, making it the largest contributor to melanoma mortality.

Objectives

Our study aim was to perform a rare-variant allele (RVA) analysis of whole-exome sequencing of patients with NM and non-NM (minor allele frequency ≤ 1% non-Finnish European) for a set of 500 candidate genes potentially implicated in melanoma.

Methods

This study recruited 131 participants with NM and 194 with non-NM from South-east Queensland and patients with NM from Victoria to perform a comparative analysis of possible genetic differences or similarities between the two melanoma cohorts.

Results

Phenotypic analysis revealed that a majority of patients diagnosed with NM were older males with a higher frequency of fair skin and red hair than is seen in the general population. The distribution of common melanoma polygenic risk scores was similar in patients with NM and non-NM, with over 28% in the highest quantile of scores. There was also a similar frequency of carriage of familial/high-penetrant melanoma gene and loss-of-function variants. We identified 39 genes by filtering 500 candidate genes based on the greatest frequency in NM compared with non-NM cases. The genes with RVAs of greatest frequency in NM included PTCH1, ARID2 and GHR. Rare variants in the SMO gene, which interacts with PTCH1 as ligand and receptor, were also identified, providing evidence that the Hedgehog pathway may contribute to NM risk. There was a cumulative effect in carrying multiple rare variants in the NM-associated genes. A 14.8-fold increased ratio for NM compared with non-NM was seen when two RVAs of the 39 genes were carried by a patient.

Conclusions

This study highlights the importance of considering frequency of RVA to identify those at risk of NM in addition to known high penetrance genes.
Benefit of skin surgical revision in high-risk basal cell carcinoma according to histopathological margins
Authors: Reynaud Bénédicte , Jacquemus Julien , Chabaud Sylvie , Ouldbey Yaelle , Darnis Sophie , Amini-Adle Mona
Published: September 2023

This article investigated the impact of histological margins on recurrence for high-risk basal cell carcinomas and analysed the existence of a benefit of surgical revision in the case of inframillimetric margins.
Evolving challenges of leadership in surgery to improve inclusivity, representation, and well-being
Authors: Mishra Kritika , Kovoor Joshua G , Gupta Aashray K , Bacchi Stephen , Lai Christine S , Stain Steven C , Maddern Guy J
Published: September 2023

Background

Leadership is a complex and demanding process crucial to maintaining quality in surgical systems of care. Once an autocratic practice, modern-day surgical leaders must demonstrate inclusivity, flexibility, emotional competence, team-building, and a multidisciplinary approach. The complex healthcare environment challenges those in leadership positions. The aim of this narrative review was to consolidate the major challenges facing surgeons today and to suggest evidence-based strategies to support surgical leaders.

Methods

Google Scholar, PubMed, MEDLINE, and Ovid databases were searched to review literature on the challenges faced by surgical leaders. The commonly identified areas that compromise inclusivity and productive leadership practices were consolidated into 10 main subheadings. Further research was conducted using the aforementioned databases to outline the importance of addressing such challenges, and to consolidate evidence-based strategies to resolve them.

Results

The importance of increasing representation of marginalized groups in leadership positions, including women, ethnic groups, the queer community, and ageing professionals, has been identified by surgical colleges in many countries. Leaders must create a collegial environment with proactive, honest communication and robust reporting pathways for victims of workplace harassment. The retention of diverse, empowering, and educating leaders relies on equitable opportunities, salaries, recognition, and support. Thus, it is important to implement formal training and mentorship, burnout prevention, conflict management, and well-being advocacy.

Conclusion

There are two aspects to addressing challenges facing surgical leadership; improving advocacy by and for leaders. Systems must be designed to support surgical leaders through formal education and training, meaningful mentorship programmes, and well-being advocacy, thus enabling them to proactively and productively advocate and care for their patients, colleagues, and professional communities.
Long-term patient-reported outcomes of immediate breast reconstruction after mastectomy for breast cancer: population-based cohort study
Authors: Johnson Leigh , White Paul , Jeevan Ranjeet , Browne John , Gulliver-Clarke Carmel , O’Donoghue Joe , Mohiuddin Syed , Hollingworth William , Fairbrother Patricia , MacKenzie Mairead , Holcombe Chris , Potter Shelley
Published: September 2023

Background

Breast reconstruction is offered to improve quality of life for women after mastectomy for breast cancer, but information regarding the long-term patient-reported outcomes of different reconstruction procedures is currently lacking. The Brighter study aimed to evaluate long-term patient-reported outcomes after immediate breast reconstruction (IBR) in a population-based cohort.

Methods

Women who underwent mastectomy with IBR for breast cancer in England between 1 January 2008 and 31 March 2009 were identified from National Health Service Hospital Episode Statistics. Surviving women were invited to complete the BREAST-Q, EQ-5D-5L™, and ICECAP-A at least 12 years after the index procedure. Questionnaires were scored according to developers’ instructions and compared by IBR type.

Results

Some 1236 women underwent IBR; 343 (27.8 per cent) had 2-stage expander/implant, 630 (51.0 per cent) latissimus dorsi, and 263 (21.3 per cent) abdominal flap reconstructions, with a mean(s.d.) follow-up of 13.3(0.5) years. Women who underwent abdominal flap reconstruction reported higher scores in all BREAST-Q domains than those who had other procedures. These differences remained statistically significant and clinically meaningful after adjusting for age, ethnicity, geographical region, socioeconomic status, smoking, BMI, and complications. The greatest difference was seen in scores for satisfaction with breasts; women who had abdominal flap reconstructions reported scores that were 13.17 (95 per cent c.i. 9.48 to 16.87) points; P < 0.001) higher than those among women who had two-stage expander/implant procedures. Women who underwent latissimus dorsi reconstruction reported significantly more pain/discomfort on the EQ-5D-5L™, but no other differences between procedures were seen.

Conclusion

Long-term patient-reported outcomes are significantly better following abdominal flap reconstruction than other traditional procedure types. These findings should be shared with women considering IBR to help them make informed decisions about their surgical options.
Impact of autofluorescence for detection of parathyroid glands during thyroidectomy on postoperative parathyroid hormone levels: parallel multicentre randomized clinical trial
Authors: Bergenfelz Anders , Barczynski Marcin , Heie Anette , Muth Andreas , Passler Christian , Schneider Max , Wierzbicka Paulina , Konturek Alexander , Brauckhoff Katrin , Elf Anna-Karin , Dahlberg Jakob , Hermann Michael
Published: September 2023

Background

Techniques for autofluorescence have been introduced to visualize the parathyroid glands during surgery and to reduce hypoparathyroidism after thyroidectomy.

Methods

This parallel multicentre RCT investigated the use of Fluobeam® LX to visualize the parathyroid glands by autofluorescence during total thyroidectomy compared with no use. There was no restriction on the indication for surgery. Patients were randomized 1 : 1 and were blinded to the group allocation. The hypothesis was that autofluorescence enables identification and protection of the parathyroid glands during thyroidectomy. The primary endpoint was the rate of low parathyroid hormone (PTH) levels the day after surgery.

Results

Some 535 patients were randomized, and 486 patients received an intervention according to the study protocol, 246 in the Fluobeam® LX group and 240 in the control group. Some 64 patients (26.0 per cent) in the Fluobeam® LX group and 77 (32.1 per cent) in the control group had low levels of PTH after thyroidectomy (P = 0.141; relative risk (RR) 0.81, 95 per cent c.i. 0.61 to 1.07). Subanalysis of 174 patients undergoing central lymph node clearance showed that 15 of 82 (18 per cent) in the Fluobeam® LX group and 31 of 92 (33 per cent) in the control group had low levels of PTH on postoperative day 1 (P = 0.021; RR 0.54, 0.31 to 0.93). More parathyroid glands were identified during operation in patients who had surgery with Fluobeam® LX, and fewer parathyroid glands in the surgical specimen on definitive histopathology. No specific harm related to the use of Fluobeam® LX was reported.

Conclusion

The use of autofluorescence during thyroidectomy did not reduce the rate of low PTH levels on postoperative day 1 in the whole group of patients. It did, however, reduce the rate in a subgroup of patients. Registration number: NCT04509011 (http://www.clinicaltrials.gov).
Long-term outcome after surgical resection of non-high-risk gastrointestinal stromal tumours without adjuvant therapy
Authors: Berndsen Marta , Renberg Sara , Hølmebakk Toto , Hancke Emma , Puls Florian , Karlsson Fredrik , Stoldt Stephan , Bjerkehagen Bodil , Haglund de Flon Felix , Muth Andreas , Papakonstantinou Andri , Boye Kjetil , Lindskog Stefan
Published: September 2023

Background

Gastrointestinal stromal tumour (GIST) is the most common intra-abdominal sarcoma. Risk classification systems, commonly the modified National Institutes of Health consensus criteria, identify tumour properties relating to patient outcomes. However, owing to limited long-term evidence, most guidelines recommend up to 10-year follow-up for all risk groups except very low-risk GIST.

Methods

This retrospective multicentre study included patients who had complete resection of primary, non-metastatic GIST from three Scandinavian sarcoma centres: Gothenburg (2004–2020), Stockholm (2000–2019), and Oslo (2000–2017). Medical records were reviewed for clinical details regarding diagnosis, treatment, and follow-up, and recurrence-free and disease-specific survival evaluated.

Results

The total cohort consisted of 1213 patients with GIST. High-risk patients and those treated with tyrosine kinase inhibitors were excluded. The remaining 649 patients were included in the present analysis: 118 with very low-, 381 with low-, and 150 with intermediate-risk GISTs. Five-year recurrence-free survival rates were 100, 98.5, and 100 per cent for the intermediate-, low-, and very low-risk groups respectively (P = 0.246). Disease-specific survival rates 10 years after surgery were 100, 98.4, and 100 per cent for the intermediate-, low-, and very low-risk groups respectively (P = 0.262).

Conclusion

Patients with completely resected non-high-risk GISTs have an excellent long-term outcome, irrespective of risk group. Follow-up programmes to detect disease recurrences in these patients are probably not indicated.
Neuromelanin accumulation drives endogenous synucleinopathy in non-human primates
Authors: Chocarro Julia , Rico Alberto J , Ariznabarreta Goiaz , Roda Elvira , Honrubia Adriana , Collantes María , Peñuelas Iván , Vázquez Alfonso , Rodríguez-Pérez Ana I , Labandeira-García José L , Vila Miquel , Lanciego José L
Published: September 2023

Although neuromelanin is a dark pigment characteristic of dopaminergic neurons in the human substantia nigra pars compacta, its potential role in the pathogenesis of Parkinson’s disease (PD) has often been neglected since most commonly used laboratory animals lack neuromelanin. Here we took advantage of adeno-associated viral vectors encoding the human tyrosinase gene for triggering a time-dependent neuromelanin accumulation within substantia nigra pars compacta dopaminergic neurons in macaques up to similar levels of pigmentation as observed in elderly humans. Furthermore, neuromelanin accumulation induced an endogenous synucleinopathy mimicking intracellular inclusions typically observed in PD together with a progressive degeneration of neuromelanin-expressing dopaminergic neurons.

Moreover, Lewy body-like intracellular inclusions were observed in cortical areas of the frontal lobe receiving dopaminergic innervation, supporting a circuit-specific anterograde spread of endogenous synucleinopathy by permissive trans-synaptic templating.

In summary, the conducted strategy resulted in the development and characterization of a new macaque model of PD matching the known neuropathology of this disorder with unprecedented accuracy. Most importantly, evidence is provided showing that intracellular aggregation of endogenous α-synuclein is triggered by neuromelanin accumulation, therefore any therapeutic approach intended to decrease neuromelanin levels may provide appealing choices for the successful implementation of novel PD therapeutics.
Extracellular vesicles set the stage for brain plasticity and recovery by multimodal signalling
Authors: Hermann Dirk M , Peruzzotti-Jametti Luca , Giebel Bernd , Pluchino Stefano
Published: September 2023

Extracellular vesicles (EVs) are extremely versatile naturally occurring membrane particles that convey complex signals between cells. EVs of different cellular sources are capable of inducing striking therapeutic responses in neurological disease models. Differently from pharmacological compounds that act by modulating defined signalling pathways, EV-based therapeutics possess multiple abilities via a variety of effectors, thus allowing the modulation of complex disease processes that may have very potent effects on brain tissue recovery. When applied in vivo in experimental models of neurological diseases, EV-based therapeutics have revealed remarkable effects on immune responses, cell metabolism and neuronal plasticity. This multimodal modulation of neuroimmune networks by EVs profoundly influences disease processes in a highly synergistic and context-dependent way. Ultimately, the EV-mediated restoration of cellular functions helps to set the stage for neurological recovery.

With this review we first outline the current understanding of the mechanisms of action of EVs, describing how EVs released from various cellular sources identify their cellular targets and convey signals to recipient cells. Then, mechanisms of action applicable to key neurological conditions such as stroke, multiple sclerosis and neurodegenerative diseases are presented. Pathways that deserve attention in specific disease contexts are discussed. We subsequently showcase considerations about EV biodistribution and delineate genetic engineering strategies aiming at enhancing brain uptake and signalling.

By sketching a broad view of EV-orchestrated brain plasticity and recovery, we finally define possible future clinical EV applications and propose necessary information to be provided ahead of clinical trials. Our goal is to provide a steppingstone that can be used to critically discuss EVs as next generation therapeutics for brain diseases.