bluuebunny/crossref_metadata_2025 huggingface dataset:
μCT ANALYSIS AND 3D MODELLING OF COMPARATIVE FLUID PERMEABILITY OF HUMAN TALI FOLLOWING THREE DIFFERENT CLINICAL PROCEDURES: NANOFRACTURE, MICROFRACTURE, AND FINE WIRE DRILLING
Authors: Warren James , Canden Ahranee , Farndon Mark , Brockett Claire
Published: November 2023

Objectives

The aim of this work was to compare the different techniques and the different fluid permeability of the tissue following each technique through assessing the flow of radiopaque contrast agent using μCT image analysis and 3D modelling.

Methods

Donated human tali specimens (n=12) were prepared through creating a 10mm diameter chondral defect in three different regions of each talus. Each region then underwent one of three surgical techniques: 1) Fine wire drilling, 2) Nanofracture or 3) Microfracture, equidistant sites in each defect to ensure even distribution. Each region then had an addition of 0.1 ml radiopaque contrast agent (Omnipaque™ 300), imaged using a clinical μCT scanner (SCANCO Medical AG, 73.6 μm resolution). Each μCT scan was segmented using Slicer 3D software (The Slicer Community, 2023 3D Slicer (5.2.2)). The segmentation package was used to segment the bone and contrast agent regions in each different surgical site of each sample. Each defect site was created into a cylinder and the ratio of segmented pixels of contrast agent against bone.

Results

The μCT analysis indicated that across the 12 samples, eight nanofracture regions demonstrated flow of the contrast agent either to the depth of the fracture site or deeper. Some lateral flow was also observed in these sites. eight microfracture regions demonstrated that the flow of the contrast agent was localised to the fracture site and a preferential flow laterally. In only one sample, did a fine wire drilling region demonstrate any fluid flow. In this sample, contrast agent had permeated through the drilling site to the bottom and some sub-site permeation was observed. However, in all samples that showed no permeation of contrast agent through the fracture site, a layer of contrast agent on the chondral surface or minor permeation through to the sub-chondral surface. Segmentation of each sample site showed a significant increase (n=12, p<0.05) in fluid flow of the contrast agent in the nanofracture sites (11%) compared to microfracture (5%) and fine wire drilling (2%).

Conclusions

Nanofracture showed significantly improved fluid permeability throughout the surrounding trabecular structure, when compared to microfracture and fine wire drilling. Microfracture appears to allow some fluid flow, but only confined to the immediate area around the fracture site, while fine wire drilling appears to allow a comparably small amount, if not no fluid flow through the surrounding trabecular tissue. This conclusion is reinforced by previous literature that concluded the damage to the structure of the trabecular tissue is reduced when using nanofracture, compared to the other two techniques.

Declaration of Interest

(a) fully declare any financial or other potential conflict of interest
EVALUATING THE UTILITY OF SPECT/CT FOR THE IDENTIFICATION OF CARTILAGE LESIONS: A SYSTEMATIC REVIEW
Authors: Rix Larissa , Tushingham Samuel , Wright Karina , Snow Martyn
Published: November 2023

Objective

A common orthopaedic pain found in a wide spectrum of individuals, from young and active to the elderly is anterior knee pain (AKP). It is a multifactorial disorder which is thought to occur through muscular imbalance, overuse, trauma, and structural malalignment. Over time, this can result in cartilage damage and subsequent chondral lesions. Whilst the current gold standard for chondral lesion detection is MRI, it is not a highly sensitive tool, with around 20% of lesions thought to be mis-diagnosed by MRI. Single-photon emission computerised tomography with conventional computer tomography (SPECT/CT) is an emerging technology, which may hold clinical value for the detection of chondral lesions. SPECT/CT may provide valuable diagnostic information for AKP patients who demonstrate absence of structural change on other imaging modalities. This review systematically assessed the value of SPECT/CT as an imaging modality for knee pain, and its ability to diagnose chondral lesions for patients who present with knee pain.

Methods

Using PRISMA guidelines, a systematic search was carried out in PubMed, Science Direct, and Web of Knowledge, CINAHL, AMED, Ovid Emcare and Embase. Inclusion criteria consisted of any English language article focusing on the diagnostic value of SPECT/CT for knee chondral lesions and knee pain. Furthermore, animal or cadaver studies, comparator technique other than SPECT/CT or patients with a pathology other than knee chondral lesions were excluded from the study. Relevant articles underwent QUADAS-2 bias assessment.

Results

11,982 manuscripts were identified, and the titles were screened for relevance. Seven studies were selected as being appropriate and were subjected to QUADAS-2 assessment. All 7 articles scored low for bias. Two papers deemed that the ICRS score of chondral lesions at intraoperative assessment correlated with SPECT/CT tracer uptake. Two studies concluded that MRI significantly correlated with SPECT/CT tracer uptake, with some instances whereby SPECT/CT identified more chondral lesions than MRI. Two papers compared bone scintigraphy (BS) to SPECT/CT and concluded that SPECT/CT was not only able to identify more chondral lesions than BS, but also localise and characterise the lesions.

Conclusion

Evidence implies that SPECT/CT may be a useful imaging modality for the detection and localisation of cartilage lesions, particularly in discrepant cases whereby there is an absence of lesions on other imaging modalities, or a lack of correspondence with patients’ symptoms. More studies would be of value to confirm the conclusions of this review.

Declaration of Interest

(b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
SYNOVIAL FLUID PROTEOMICS AND BIOINFORMATICS HIGHLIGHTS POTENTIAL MECHANISMS OF UMBILICAL CORD-MSC INDUCED RADIOLOGICAL IMPROVEMENT IN AN OVINE MODEL OF OSTEOARTHRITIS
Authors: Wright Karina , McDonald Jamie , Mennan Claire , Perry Jade , Peffers Mandy , Hulme Charlotte
Published: November 2023

Objectives

A promising therapy for early osteoarthritis (OA) is the transplantation of human umbilical cord-derived mesenchymal stromal cells (hUC-MSCs). The synovial fluid (SF) from a pre-clinical ovine model treated with hUC-MSCs has been profiled using proteomics and bioinformatics to elucidate potential mechanisms of therapeutic effect.

Methods

Four weeks after a medial meniscus transection surgery, sheep were injected with 107 hUC-MSCs in Phosphate Buffered Saline (PBS) or PBS only (n=7) and sacrificed at 12 weeks. SF was normalised for protein abundance (ProteoMinerTM) and analysed using label-free quantitation proteomics. Bioinformatics analyses (Ingenuity Pathway Analysis (IPA) and STRING) were used to assess differentially regulated functions from the proteomic data. Human orthologues were identified for the ovine proteins using UniProt and DAVID resources and proteins that were ≥±1.3 fold differentially abundant between treatment groups, were included in the bioinformatics analyses.

Results

hUC-MSC treated animals demonstrated significantly less joint space narrowing. Nineteen SF proteins were differentially abundant in treated cf. control sheep (FC±2.0; p<0.05). Biglycan (a small leucine-rich proteoglycan of the cartilage extracellular matrix) abundance was increased by 2.1 fold in treated compared to untreated sheep (p=0.024). IPA indicated that lipid synthesis (z-score=1.772; p=0.00267) and immune cell migration pathways (cell movement of mononuclear leukocytes: z-score=1.761; p=0.00259), amongst others, were likely to be activated in the treated sheep. Conversely, tissue damage (z-score=−2; p=0.00019), senescence (z-score=−1.981; p=0.00007) and necrosis (z-score=−1.728; p=0.00829) associated pathways as well as inflammation (z-score=−1.718; p=0.00057) and vascular permeability (z-score=−1.698; p=0.00002) were likely to be inhibited in treated cf. untreated sheep.

Conclusions

hUC-MSC treatment prevented/delayed OA progression, demonstrated via a reduction in joint space narrowing. SF proteome bioinformatics revealed potential mechanisms of therapeutic action related to immunomodulation and the inhibition of multiple cell death, and tissue damage associated pathways. Further, a potential predicted upregulation in lipid synthesis in treated sheep represents a novel mechanism warranting further investigation. Additional work is required to validate these discovery phase proteomic findings in studies which specifically target and manipulate the proposed mechanisms highlighted.

Declaration of Interest

(b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
PATIENT-SPECIFIC DISTAL FEMORAL OSTEOTOMY REDUCES SURGICAL TIME: DEMONSTRATION OF A NOVEL PATIENT-SPECIFIC TECHNIQUE
Authors: Bishop Mathew , Zaffagnini Stefano , Grassi Alberto , Fabbro Giacomo Dal , Smyrl Graeme , Roberts Samuel , MacLeod Alisdair
Published: November 2023

Background

Distal femoral osteotomy is an established successful procedure which can delay the progression of arthritis and the need for knee arthroplasty. The surgery, however, is complex and lengthy and consequently it is generally the preserve of highly experienced specialists and thus not widely offered. Patient specific instrumentation is known to reduce procedural complexity, time, and surgeons’ anxiety levels1 in proximal tibial osteotomy procedures. This study evaluated a novel patient specific distal femoral osteotomy procedure (Orthoscape, Bath, UK) which aimed to use custom-made implants and instrumentation to provide a precision correction while also simplifying the procedure so that more surgeons would be comfortable offering the procedure.

Presenting problem

Three patients (n=3) with early-stage knee arthritis presented with valgus malalignment, the source of which was predominantly located within the distal femur, rather than intraarticular. Using conventional techniques and instrumentation, distal femoral knee osteotomy cases typically require 1.5–2 hours surgery time. The use of bi-planar osteotomy cuts have been shown to improve intraoperative stability as well as bone healing times2. This normally also increases surgical complexity; however, multiple cutting slots can be easily incorporated into patient specific instrumentation.

Clinical management

All three cases were treated at a high-volume tertiary referral centre (Istituto Ortopedico Rizzoli, Bologna) using medial closing wedge distal femoral knee osteotomies by a team experienced in using patient specific osteotomy systems3. Virtual surgical planning was conducted using CT-scans and long-leg weight-bearing x-rays (Orthoscape, Bath, UK). Patient specific surgical guides and custom-made locking plates were design for each case. The guides were designed to allow temporary positioning, drilling and bi-planar saw-cutting. The drills were positioned such that the drills above and below the osteotomy became parallel on closing following osteotomy wedge removal. This gave reassurance of the achieved correction allowed the plate to be located precisely over the drills. All screw lengths were pre-measured.

Discussion

The surgical time reduced to approximately 30 minutes by the third procedure. It was evident that surgical time was saved because no intraoperative screw length measurements were required, relatively few x-rays were used to confirm the position of the surgical guide, and the use of custom instrumentation significantly reduced the surgical inventory. The reduced invasiveness and ease of surgery may contribute to faster patient recovery compared to conventional techniques. The final post-operative alignment was within 1° of the planned alignment in all cases.

Declaration of Interest

(a) fully declare any financial or other potential conflict of interest
HUMAN MONOCYTES AND MESENCHYMAL STEM/STROMAL CELLS CO-CULTURED IN FIBRIN HAVE A PRO-REPAIR PHENOTYPE THAT INFLUENCES CHONDROCYTE ACTIVITY
Authors: Alkhrayef Mohammad , Muhammad Hayat , Hosni Rawiya Al , McCaskie Andrew , Birch Mark
Published: November 2023

Objectives

Tissue repair is believed to rely on tissue-resident progenitor cell populations proliferating, migrating, and undergoing differentiation at the site of injury. During these processes, the crosstalk between mesenchymal stromal/stem cells (MSCs) and macrophages has been shown to play a pivotal role. However, the influence of extracellular matrix (ECM) remodelling in this crosstalk, remains elusive.

Methods

Human MSCs cultured on tissue culture plastic (TCP) and encased within fibrin in vitro were treated with/without TNFα and IFNγ. Human monocytes were cocultured with untreated/pretreated MSCs on TCP or within fibrin. After seven days, the conditioned media (CM) were collected. Human chondrocytes were exposed to CM in a migration assay. The impact of TGFβ was assessed by adding an inhibitor (TGFβRi). Cell activity was assessed using RT-qPCR and XL-protein-profiler-array.

Results

Previously, we demonstrated that culturing human MSCs within 3D-environments significantly enhances their immunoregulatory activity in response to pro-inflammatory stimuli. In this study, monocytes were co-cultured with MSCs within fibrin, acquiring a distinct M2-like repair macrophage phenotype in contrast to TCP co-cultures. MSC/macrophage CM characterization using a protein array demonstrated differences in release of several factors, including chemokines, growth factors and ECM components. Chondrocyte migration was significantly reduced in CM from untreated MSC/monocytes co-cultures in fibrin compared to CM of untreated MSCs/monocytes on TCP. This impact on migration was not seen with chondrocytes cultured in CM of monocytes co-cultured with pretreated MSCs in fibrin. The CM of monocytes co-cultured with pretreated MSCs in fibrin up-regulates COL2A1 and SOX9 compared to TCP. Chondrogenesis and migration were TGFβ dependent.

Conclusion

MSC/macrophage crosstalk and responsiveness to cytokines are influenced by the ECM environment, which subsequently impacts tissue-resident cell migration and chondrogenesis. The direct effects of ECM on MSC/macrophage secretory phenotype is complemented by the dynamic ECM binding and release of growth factors such as TGFβ.

Declaration of Interest

(b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
SENESCENCE OR APOPTOSIS: CHONDROCYTE RESPONSE TO INFLAMMATION IN VITRO IS DEPENDENT ON ITS DIMENSIONAL ENVIRONMENT
Authors: Strangmark Estelle , Wang Jia Hua , Hosni Rawiya Al , Muhammad Hayat , Alkhrayef Mohammad , Robertson-Waters Eve , MacMillan Alexandra , Gompels Benjamin , Vogt Antonia , Khan Wasim , Birch Mark , McCaskie Andrew
Published: November 2023

BACKGROUND

Cell culture on tissue culture plastic (TCP) is widely used across biomedical research to understand the in vivo environment of a targeted biological system. However, growing evidence indicates that the characteristics of cells investigated in this way differ substantially from their characteristics in the human body. The limitations of TCP monolayer cell cultures are especially relevant for chondrocytes, the cell population responsible for producing cartilage matrix, because their zonal organization in hyaline cartilage is not preserved in a flattened monolayer assay.

OBJECTIVE

Here, we contrast the response of primary human chondrocytes to inflammatory cytokines, tumor necrosis factor-alpha and interferon-gamma, via transcriptional, translational, and histological profiling, when grown either on TCP or within a 3D cell pellet (scaffold-less). We focus on anti-apoptotic (Bcl2), pro-apoptotic (Bax, Mff, Fis1), and senescent (MMP13, MMP1, PCNA, p16, p21) markers.

RESULTS

We find that the 3D environment of the chondrocyte has a profound effect on the behavior and fate of the cell; in TCP monolayer cultures, chondrocytes become anti-apoptotic and undergo senescence in response to inflammatory cytokines, whereas in 3D cell pellet cultures, they exhibit a pro-apoptotic response.

CONCLUSION

Our findings demonstrate that chondrocyte culture environment plays a pivotal role in cell behavior, which has important implications for the clinical applicability of in vitro research of cartilage repair. Although there are practical advantages to 2D cell cultures, our data suggest researchers should be cautious when drawing conclusions if they intend to extrapolate findings to in vivo phenomena. Our data demonstrates opposing chondrocyte responses in relation to apoptosis and senescence, which appear to be solely reliant on the environment of the culture system. This biological observation highlights that proper experimental design is crucial to increase the clinical utility of cartilage repair experiments and streamline their translation to therapy development.

Declaration of Interest

(b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
CLINICAL VALUE OF ELECTIVE POSTOPERATIVE RADIOGRAPHS IN TOTAL JOINT REPLACEMENT
Authors: Rajab Ali , Ponsworno Kimberly , Keehan Robert , Ahmad Riaz
Published: November 2023

Background

Post operative radiographs following total joint arthroplasty are requested as part of routine follow up in many institutions. These studies have a significant cost to the local departments, in terms of financial and clinic resources, however, previous research has suggested they may not alter the course of the patients treatment. The purpose of this study was to assess the significance of elective post operative radiographs on changes in management of patients who underwent total joint arthroplasty.

Method

All patients who underwent total knee arthroplasty and total hip arthroplasty at a District General Hospital from 2019 to 2020 were included. Data was collected retrospectively from medical records and radiograph requests. Alterations to clinical management based on radiographic findings were reviewed in clinic letters.

Results

A total of 227 Total joint arthroplasty were retrieved. With 111(49%) total hip arthroplasty and 116 (51%) total knee arthroplasty. 54 were excluded due to having no clinical follow up and 173 met inclusion criteria. 56 (32%) had their post operative elective radiograph, while 93 (53.8%) patients had none. There were no abnormalities detected from the elective radiographs and none of the patients returned to the theatre. 24 patients (13%) presented with symptoms and had non-elective radiographs, 16 (67%) did not have any interventions and 8 (4.6%) required intervention and were taken to theatre. Discussion: Not performing these radiographs saves time, cost, and prevents unnecessary radiation exposure. In our institution, a 2-view joint radiograph costs £29 and takes roughly 15 minutes. This does not include indirect costs of additional clinic time and patient waiting time. In the larger context, the cost associated with elective radiographs is significant and our data suggests that routine post-operative radiographs are not beneficial as part of standard post-operative protocol for asymptomatic patients. However, performing imaging remains beneficial for patients who re-present with symptoms.

Conclusion

Routine elective post-operative joint radiographs did not detect any true abnormalities. Information from elective radiographs has no clinical significance and did not change management. Therefore, this study recommends that there is no rationale requesting elective post-operative joint radiographs.

Declaration of Interest

(b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Should they stay or should they go?
Authors: Baig Sultan
Published: November 2023

This article explores the responses of Western countries to refugee crises. European countries have been pioneers in articulating frameworks to address the issues of refugees and migration, since World War II. On the other hand, the same European countries are articulating policies to block refugees from reaching their territory, weaponizing and securitizing them for political objectives. This article puts the European outcry for humanitarianism to the test, to display the true objectives behind actions and policies. Furthermore, this research draws on principles and goals of human security and securitization politics, asking how the refugee crisis fits within the debates of those political thoughts.
Spectral precision improvement with demagnifying spectral images in spectroscopic nanoscopy
Authors: Song Ki-Hee , Zhang Yang
Published: November 2023

Spectroscopic nanoscopy (SN) has been recognized as a key functional imaging tool in cell biology and chemistry because it offers the unique capability to simultaneously obtain the spatial and spectral information for single molecules. However, it has an intrinsic issue in using the limited photon budget from single emitters divided into two imaging channels to concurrently acquire spatial and spectral images. Accordingly, this issue lowers the spatial localization and spectral precision. Although several techniques have been introduced to improve the spatial precision in SN, improving the spectral precision has been overlooked so far. Here we propose a method to improve the spectral precision by optically manipulating the width of the spectroscopic signatures using a demagnifier. We evaluate its performance using numerical simulations with systematic investigations of several underlying optimal parameters such as the demagnification factor and the integration width in the proposed configuration. We also present achievable spectral precision values with different signal and background levels. Compared to the existing SN system, the 3× demagnifier-based configuration shows an approximate 35% improvement, from 2.9 nm to 1.9 nm, in the spectral precision at the 1000 photons signal level.
Energy resolving dark-field imaging with dual phase grating interferometer
Authors: Cai Xuebao , Tan Yuhang , Zhang Xin , Yang Jiecheng , Xu Jinyou , Zheng Hairong , Liang Dong , Ge Yongshuai
Published: November 2023

X-ray dark-filed imaging is a powerful approach to quantify the dimension of micro-structures of the object. Often, a series of dark-filed signals have to be measured under various correlation lengths. For instance, this is often achieved by adjusting the sample positions by multiple times in Talbot-Lau interferometer. Moreover, such multiple measurements can also be collected via adjustments of the inter-space between the phase gratings in dual phase grating interferometer. In this study, the energy resolving capability of the dual phase grating interferometer is explored with the aim to accelerate the data acquisition speed of dark-filed imaging. To do so, both theoretical analyses and numerical simulations are investigated. Specifically, the responses of the dual phase grating interferometer at varied X-ray beam energies are studied. Compared with the mechanical position translation approach, the combination of such energy resolving capability helps to greatly shorten the total dark-field imaging time in dual phase grating interferometer.
Field trial of concurrent co-cable and co-trench optical fiber online identification based on ensemble learning
Authors: Li Yunbo , Zhang Dechao , Wang Zhiwei , Yang Hui , Yu Tiankuo , Yao Qiuyan , Liu Sheng , Wang Dong , Zhao Yang , Li Han , Deng Chen , Chen Haotian , Xu Ruiwan
Published: November 2023

The co-route optical fibers, comprising both co-cable and co-trench fibers, pose a significant potential risk to network service quality assurance by operators. They are incapable of achieving high-precision recognition and visual state management. In this study, we gathered both static and dynamic optical fiber data using a linewidth tunable light source (LTLS) and introduced a multimodal detection architecture that applies ensemble learning to the collected data. This constitutes what we believe to be the first field trial of concurrent recognition of optical fibers found both in co-cables and co-trenches. To identify co-cable fibers, we employed a double-layer cascaded Random Forest (DLC-RF) model based on the static features of fibers. For co-trench fiber, the dynamic characteristics of fiber vibrations are utilized in combination with multiple independent curve similarity contrast learners for classifying tasks. The proposed architecture is capable of automatically detecting the condition of the optical fiber and actively identifying the same routing segment within the network, eliminating the need for human intervention and enabling the visualization of passive optical fiber resources. Finally, after rigorous testing and validation across 11 sites in a typical urban area, including aggregation and backbone scenarios within the operator's live network environments, we have confirmed that the solution's ability to identify co-routes is accurate, exceeding 95%. This provides strong empirical evidence of its effectiveness.
Chaotic phase noise-like encryption based on geometric shaping for coherent data center interconnections
Authors: Zeng Wenjun , Zhang Chongfu , Liang Xinshuai , Luo Yufeng , Wang Xue , Qiu Kun
Published: November 2023

The network traffic of data centers (DCs) has increased unprecedentedly with the rapid development of digital economy. However, the data transmission faces security threats in the distributed optical interconnection and intensive interaction of DC networks. In this paper, we propose a chaotic phase noise-like encryption algorithm using geometric shaping (GS) for coherent DC interconnections (DCIs). A GS constellation is used to improve transmission performance, and it is combined with coherent equalization algorithms to improve security performance. Then, a chaotic encryption is designed based on phase noise-like transformation (PNLT). The data are effectively scrambled, and the confusion level of phase can be increased. Finally, 216 Gb/s 8-quadrature amplitude modulation (8-QAM) encrypted data are successfully verified on a 240 km transmission link of DCIs. The results show that this scheme can achieve a bit error rate (BER) performance gain of 1.1 dB and provide a highly compatible solution for realizing security enhanced DCIs.
Optomechanical effects caused by non-zero field quantities in multiple evanescent waves
Authors: Li Yaxin , Yu Xinning , Qu Tiantao , Ng Jack , Lin Zhifang , Zhang Lei , Chen Jun
Published: November 2023

Evanescent waves, with their high energy density, intricate local momentum, and spatial distribution of spins, have been the subject of extensive recent study. These waves offer promising applications in near-field particle manipulation. Consequently, it becomes imperative to gain a deeper understanding of the impacts of scattering and gradient forces on particles in evanescent waves to enhance and refine the manipulation capabilities. In this study, we employ the multipole expansion theory to present analytical expressions for the scattering and gradient forces exerted on an isotropic sphere of any size and composition in multiple evanescent waves. The investigation of these forces reveals several unusual optomechanical phenomena. It is well known that the scattering force does not exist in counter-propagating homogeneous plane waves. Surprisingly, in multiple pairs of counter-propagating evanescent waves, the scattering force can arise due to the nonzero orbital momentum (OM) density and/or the curl part of the imaginary Poynting momentum (IPM) density. More importantly, it is found that the optical scattering force can be switched on and off by simply tuning the polarization. Furthermore, optical forces typically vary with spatial position in an interference field. However, in the interference field generated by evanescent waves, the gradient force becomes a spatial constant in the propagating plane as the particle’s radius increases. This is attributed to the decisive role of the non-interference term of the electromagnetic energy density gradient. Our study establishes a comprehensive and rigorous theoretical foundation, propelling the advancement and optimization of optical manipulation techniques harnessed through multiple evanescent waves. Specifically, these insights hold promise in elevating trapping efficiency through precise control and manipulation of optical scattering and gradient forces, stimulating further explorations.
Structured illumination ptychography and at-wavelength characterization with an EUV diffuser at 13.5 nm wavelength
Authors: Eschen Wilhelm , Liu Chang , Steinert Michael , Penagos Molina Daniel S. , Siefke Thomas , Zeitner Uwe D. , Kaspar Jörg , Pertsch Thomas , Limpert Jens , Rothhardt Jan
Published: November 2023

Structured illumination is essential for high-performance ptychography. Especially in the extreme ultraviolet (EUV) range, where reflective optics are prevalent, the generation of structured beams is challenging and, so far, mostly amplitude-only masks have been used. In this study, we generate a highly structured beam using a phase-shifting diffuser optimized for 13.5 nm wavelength and apply this beam to EUV ptychography. This tailored illumination significantly enhances the quality and resolution of the ptychography reconstructions. In particular, when utilizing the full dynamics range of the detector, the resolution has been improved from 125 nm, when using an unstructured beam, to 34 nm. Further, ptychography enables the quantitative measurement of both the amplitude and phase of the EUV diffuser at 13.5 nm wavelength. This capability allows us to evaluate the influence of imperfections and contaminations on its “at wavelength” performance, paving the way for advanced EUV metrology applications and highlighting its importance for future developments in nanolithography and related fields.
Random laser emission at 1064 and 1550 nm in a Er/Yb co-doped fiber-based dual-wavelength random fiber laser
Authors: Li Zhe , She Shengfei , Li Gang , Gao Qi , Ju Pei , Gao Wei , Sun Chuandong , Wang Yishan
Published: November 2023

Dual-wavelength fiber lasers operating with a wide spectral separation are of considerable importance for many applications. In this study, we propose and experimentally explore an all-fiberized dual-wavelength random fiber laser with bi-directional laser output operating at 1064 and 1550 nm, respectively. A specially designed Er/Yb co-doped fiber, by optimizing the concentrations of the co-doped Er, Yb, Al and P, was developed for simultaneously providing Er ions gain and Yb ions gain for RFL. Two spans of single mode passive fibers are employed to providing random feedback for 1064 and 1550 nm random lasing, respectively. The RFL generates 5.35 W at 1064 nm and 6.61 W at 1550 nm random lasers. Two power amplifiers (PA) enhance the seed laser to 50 W at 1064 nm with a 3 dB bandwidth of 0.31 nm and 20 W at 1550 nm with a 3 dB bandwidth of 1.18 nm. Both the short- and long-term time domain stabilities are crucial for practical applications. The output lasers of 1064 and 1550 nm PAs are in the single transverse mode operating with a nearly Gaussian profile. To the best of our knowledge, this is the first demonstration of a dual-wavelength RFL, with a spectral separation as far as about 500 nm in an all-fiber configuration.
Effect of the nanopillar diameter on diamond silicon vacancy center spin lifetime
Authors: Lutz T. , Masuda T. , Hadden J. P. , Fescenko I. , Acosta V. M. , Tittel W. , Barclay P. E.
Published: November 2023

Color centers in diamond micro and nano-structures play an important role in a wide range of quantum technologies. However, obtaining high-quality color centers in small structures is challenging, as properties such as spin population lifetimes can be affected by the transition from a bulk to nanostructured crystal host. In this manuscript, we measure how population lifetimes of silicon vacancy center orbital states change when they are created in nanopillars whose diameters vary from 1 μm to 120 nm. We also discuss the influence of annealing methods on the silicon vacancy inhomogeneous linewidth. After selecting a sample with low inhomogeneous broadening and patterning it with nanopillars, we expected that restricted vibrational modes in the smallest structures could extend spin population lifetimes. However, we found that this effect was masked by other effects that reduced population lifetimes, suggesting that imperfections in the crystal lattice or surface damage caused by etching can influence SiV spins.
Enlarge the dynamic range of Shack-Hartmann Wavefront sensor based on biplanar image acquisition and segmentation methods.
Authors: ye shaowei , MING LI , LIXIANG ZHOU , XIN LI , HUI LI , xida Han , XIANLIN WU , Zhao Hongchao , XUDONG LIN
Published: November 2023

A typical SHWS has a limited dynamic range, which is determined by the f-number of the micro-lens. This causes the spot corresponding to the sub-aperture of the micro-lens to shift out of the corresponding range of the sub-aperture. In this paper, we propose a simple and robust method based on biplanar image acquisition and segmentation for expanding the SHWS dynamic range to a dynamic range based on avoiding the overlap of lenslet images and sufficient sampling accuracy for measurement. This also resolves the issue of mandating the determination of centroid exclusively within the corresponding detection area. We perform a comparative analysis between our proposed method and a conventional method for measuring large wavefronts, utilizing both numerical simulations and experiments. Additionally, we conducted a statistical analysis of the dynamic range of our method, and the results indicate that the dynamic range using this method has improved 2.7 to 9 times compared to the dynamic range of conventional algorithms
Experimental solutions to the high-dimensional mean king’s problem
Authors: Jaouni Tareq , Gao Xiaoqin , Arlt Sören , Krenn Mario , Karimi Ebrahim
Published: November 2023

Vaidman, Aharanov, and Albert [Phys. Rev. Lett. 58(14), 1385 (1987)10.1103/PhysRevLett.58.1385] put forward a puzzle called the mean king’s problem (MKP) that can be solved only by harnessing quantum entanglement. Prime-powered solutions to the problem have been shown to exist, but they have not yet been experimentally realized for any dimension beyond two. We propose a general first-of-its-kind experimental scheme for solving the MKP in prime dimensions (D). Our search is guided by the digital discovery framework Pytheus, which finds highly interpretable graph-based representations of quantum optical experimental setups; using it, we find specific solutions and generalize to higher dimensions through human insight. As proof of principle, we present a detailed investigation of our solution for the three-, five-, and seven-dimensional cases. We obtain maximum success probabilities of 82.3%, 56.2%, and 35.5%, respectively. We therefore posit that our computer-inspired scheme yields solutions that implement Alice’s strategy with quantum advantage, demonstrating its promise for experimental implementation in quantum communication tasks.
AimSeg: A machine-learning-aided tool for axon, inner tongue and myelin segmentation
Authors: Carrillo-Barberà Pau , Rondelli Ana Maria , Morante-Redolat Jose Manuel , Vernay Bertrand , Williams Anna , Bankhead Peter
Published: November 2023

Electron microscopy (EM) images of axons and their ensheathing myelin from both the central and peripheral nervous system are used for assessing myelin formation, degeneration (demyelination) and regeneration (remyelination). The g-ratio is the gold standard measure of assessing myelin thickness and quality, and traditionally is determined from measurements made manually from EM images–a time-consuming endeavour with limited reproducibility. These measurements have also historically neglected the innermost uncompacted myelin sheath, known as the inner tongue. Nonetheless, the inner tongue has been shown to be important for myelin growth and some studies have reported that certain conditions can elicit its enlargement. Ignoring this fact may bias the standard g-ratio analysis, whereas quantifying the uncompacted myelin has the potential to provide novel insights in the myelin field. In this regard, we have developed AimSeg, a bioimage analysis tool for axon, inner tongue and myelin segmentation. Aided by machine learning classifiers trained on transmission EM (TEM) images of tissue undergoing remyelination, AimSeg can be used either as an automated workflow or as a user-assisted segmentation tool. Validation results on TEM data from both healthy and remyelinating samples show good performance in segmenting all three fibre components, with the assisted segmentation showing the potential for further improvement with minimal user intervention. This results in a considerable reduction in time for analysis compared with manual annotation. AimSeg could also be used to build larger, high quality ground truth datasets to train novel deep learning models. Implemented in Fiji, AimSeg can use machine learning classifiers trained in ilastik. This, combined with a user-friendly interface and the ability to quantify uncompacted myelin, makes AimSeg a unique tool to assess myelin growth.
Strategies for gender mainstreaming in climate finance mobilisation in southern Africa
Authors: Gerhard Michael , Jones-Phillipson Emma , Ndeleni Xoliswa
Published: November 2023

This study examines the practice of gender mainstreaming in the context of climate finance mobilisation. It reveals how financial institutions are adopting shifts to organisational strategy, policy, and practice that advance the integration of key aspects of social sciences. This article specifically examines the role played by the Green Climate Fund’s Gender Policy in promoting a shift in the organisational strategies developed by development finance institutions and commercial banks in southern Africa. It reveals how practitioners are grappling with the evolving role of financial intermediaries in promoting a shift towards low-emissions, climate-resilient, and just development. The analysis uncovers foundational components, highlights key lessons, and identifies strategic approaches to institutionalising gender mainstreaming practices. Critically, the research reveals that whilst gender mainstreaming involves multiple practicalities, the financial institutions that have most extensively institutionalised gender mainstreaming practices have done so by recognising its normative basis and have perpetuated changes to organisational values and culture alongside more pedestrian policy amendments. One of the critical aspects of this culture shift is the recognition that transformative social impacts in climate finance are predicated on the design and implementation of projects that account for existing gender-based vulnerabilities whilst also identifying and maximising opportunities for all genders. The study builds on and contributes new knowledge to existing frameworks for understanding gender mainstreaming in relation to multilateral climate finance.
Vegetable oil-based surfactants are adjuvants that enhance the efficacy of neonicotinoid insecticides and can bias susceptibility testing in adult mosquitoes
Authors: Ashu Fred A. , Fouet Caroline , Ambadiang Marilene M. , Penlap-Beng Véronique , Kamdem Colince
Published: November 2023

Background

The standard operating procedure for testing the susceptibility of adult mosquitoes to neonicotinoid or butenolide insecticides recommends using a vegetable oil ester (Mero) as a surfactant. However, there is growing evidence that this adjuvant contains surfactants that can enhance insecticide activity, mask resistance and bias the bioassay.

Methodology/Principal findings

Using standard bioassays, we tested the effects of commercial formulations of vegetable oil-based surfactants similar to Mero on the activity of a spectrum of active ingredients including four neonicotinoids (acetamiprid, clothianidin, imidacloprid and thiamethoxam) and two pyrethroids (permethrin and deltamethrin). We found that three different brands of linseed oil soap used as cleaning products drastically enhanced neonicotinoid activity in Anopheles mosquitoes. At 1% (v/v), the surfactant reduced the median lethal concentration, LC50, of clothianidin more than 10-fold both in susceptible and in resistant populations of Anopheles gambiae. At 1% or 0.5% (v/v), linseed oil soap restored the susceptibility of adult mosquitoes fully to clothianidin, thiamethoxam and imidacloprid and partially to acetamiprid. By contrast, adding soap to the active ingredient did not significantly affect the level of resistance to permethrin or deltamethrin suggesting that vegetable oil-based surfactants specifically enhance the potency of some classes of insecticides.

Conclusions/Significance

Our findings indicate that surfactants are not inert ingredients, and their use in susceptibility testing may jeopardize the ability to detect resistance. Further research is needed to evaluate the potential, the limitations and the challenges of using some surfactants as adjuvants to enhance the potency of some chemicals applied in mosquito control.
Epigenetic, psychological, and EEG changes after a 1-week retreat based on mindfulness and compassion for stress reduction in healthy adults: Study protocol of a cross-over randomized controlled trial
Authors: Diez Gustavo G. , Martin-Subero Ignacio , Zangri Rosaria M. , Kulis Marta , Andreu Catherine , Blanco Ivan , Roca Pablo , Cuesta Pablo , García Carola , Garzón Jesús , Herradón Carlos , Riutort Miguel , Baliyan Shishir , Venero César , Vázquez Carmelo
Published: November 2023

Introduction

The main objective of the study will be to evaluate the effects of two widely used standardized mindfulness-based programs [Mindfulness-Based Stress Reduction (MBSR) and Compassion Cultivation Training (CCT)], on epigenetic, neurobiological, psychological, and physiological variables.

Methods

The programs will be offered in an intensive retreat format in a general population sample of healthy volunteer adults. During a 7-day retreat, participants will receive MBSR and CCT in a crossover design where participants complete both programs in random order. After finishing their first 3-day training with one of the two programs, participants will be assigned to the second 3-day training with the second program. The effects of the MBSR and CCT programs, and their combination, will be measured by epigenetic changes (i.e., DNA methylation biomarkers), neurobiological and psychophysiological measures (i.e., EEG resting state, EKG, respiration patterns, and diurnal cortisol slopes), self-report questionnaires belonging to different psychological domains (i.e., mindfulness, compassion, well-being, distress, and general functioning), and stress tasks (i.e., an Arithmetic Stress Test and the retrieval of negative autobiographical memories). These measures will be collected from both groups on the mornings of day 1 (pre-program), day 4 (after finishing the first program and before beginning the second program), and day 7 (post-second program). We will conduct a 3-month and a 12-month follow-up using only the set of self-report measures.

Discussion

This study aims to shed light on the neurobiological and psychological mechanisms linked to meditation and compassion in the general population. The protocol was registered at clinicaltrials.gov (Identifier: NCT05516355; August 23, 2022).
Effects of ocean acidification on growth and photophysiology of two tropical reef macroalgae
Authors: Page Heather N. , McCoy Sophie , Spencer Robert G. M. , Burnham Katherine A. , Hewett Clay , Johnson Maggie
Published: November 2023

Macroalgae can modify coral reef community structure and ecosystem function through a variety of mechanisms, including mediation of biogeochemistry through photosynthesis and the associated production of dissolved organic carbon (DOC). Ocean acidification has the potential to fuel macroalgal growth and photosynthesis and alter DOC production, but responses across taxa and regions are widely varied and difficult to predict. Focusing on algal taxa from two different functional groups on Caribbean coral reefs, we exposed fleshy (Dictyota spp.) and calcifying (Halimeda tuna) macroalgae to ambient and low seawater pH for 25 days in an outdoor experimental system in the Florida Keys. We quantified algal growth, calcification, photophysiology, and DOC production across pH treatments. We observed no significant differences in the growth or photophysiology of either species between treatments, except for lower chlorophyll b concentrations in Dictyota spp. in response to low pH. We were unable to quantify changes in DOC production. The tolerance of Dictyota and Halimeda to near-future seawater carbonate chemistry and stability of photophysiology, suggests that acidification alone is unlikely to change biogeochemical processes associated with algal photosynthesis in these species. Additional research is needed to fully understand how taxa from these functional groups sourced from a wide range of environmental conditions regulate photosynthesis (via carbon uptake strategies) and how this impacts their DOC production. Understanding these species-specific responses to future acidification will allow us to more accurately model and predict the indirect impacts of macroalgae on coral health and reef ecosystem processes.
FlgV forms a flagellar motor ring that is required for optimal motility of Helicobacter pylori
Authors: Botting Jack M. , Tachiyama Shoichi , Gibson Katherine H. , Liu Jun , Starai Vincent J. , Hoover Timothy R.
Published: November 2023

Flagella-driven motility is essential for Helicobacter pylori to colonize the human stomach, where it causes a variety of diseases, including chronic gastritis, peptic ulcer disease, and gastric cancer. H. pylori has evolved a high-torque-generating flagellar motor that possesses several accessories not found in the archetypical Escherichia coli motor. FlgV was one of the first flagellar accessory proteins identified in Campylobacter jejuni, but its structure and function remain poorly understood. Here, we confirm that deletion of flgV in H. pylori B128 and a highly motile variant of H. pylori G27 (G27M) results in reduced motility in soft agar medium. Comparative analyses of in-situ flagellar motor structures of wild-type, ΔflgV, and a strain expressing FlgV-YFP showed that FlgV forms a ring-like structure closely associated with the junction of two highly conserved flagellar components: the MS and C rings. The results of our studies suggest that the FlgV ring has adapted specifically in Campylobacterota to support the assembly and efficient function of the high-torque-generating motors.