Tunable Light-Responsive Polyurethane-urea Elastomer Driven by Photochemical and Photothermal Coupling Mechanism.

Light-driven soft actuators based on photoresponsive materials can be used to mimic biological motion, such as hand movements, without involving rigid or bulky electromechanical actuations. However, to our knowledge, no robust photoresponsive material with desireable mechanical and biological properties and relatively simple manufacture exists for robotics and biomedical applications. Herein, we report a new visible-light-responsive thermoplastic elastomer synthesized by introducing photoswitchable moieties (i.e., azobenzene derivatives) into the main chain of poly(ε-caprolactone) based polyurethane urea (PAzo). A PAzo elastomer exhibits controllable light-driven stiffness softening due to its unique nanophase structure in response to light, while possessing excellent hyperelasticity (stretchability of 575.2%, elastic modulus of 17.6 MPa, and strength of 44.0 MPa). A bilayer actuator consisting of PAzo and polyimide films is developed, demonstrating tunable bending modes by varying incident light intensities. Actuation mechanism via photothermal and photochemical coupling effects of a soft-hard nanophase is demonstrated through both experimental and theoretical analyses. We demonstrate an exemplar application of visible-light-controlled soft "fingers" playing a piano on a smartphone. The robustness of the PAzo elastomer and its scalability, in addition to its excellent biocompatibility, opens the door to the development of reproducible light-driven wearable/implantable actuators and lightweight soft robots for clinical applications.

In-depth investigation of the effect of pH on the autofluorescence properties of DPF3b and DPF3a amyloid fibrils.

Double PHD fingers 3 (DPF3) protein exists as two splicing variants, DPF3b and DPF3a, the involvement of which in human cancer and neurodegeneration is beginning to be increasingly recognised. Both isoforms have recently been identified as intrinsically disordered proteins able to undergo amyloid fibrillation. Upon their aggregation, DPF3 proteins exhibit an intrinsic fluorescence in the visible range, referred to as deep-blue autofluorescence (dbAF). Comprehension of such phenomenon remaining elusive, we investigated in the present study the influence of pH on the optical properties of DPF3b and DPF3a fibrils. By varying the excitation wavelength and the pH condition, the two isoforms were revealed to display several autofluorescence modes that were defined as violet, deep-blue, and blue-green according to their emission range. Complementarily, analysis of excitation spectra and red edge shift plots allowed to better decipher their photoselection mechanism and to highlight isoform-specific excitation-emission features. Furthermore, the observed violation to Kasha-Vavilov's rule was attributed to red edge excitation shift effects, which were impacted by pH-mediated H-bond disruption, leading to changes in intramolecular charge and proton transfer, or π-electrons delocalisation. Finally, emergence of different autofluorescence emitters was likely related to structurally distinct fibrillar assemblies between isoforms, as well as to discrepancies in the amino acid composition of their aggregation prone regions.

A Sensorized Soft Robotic Hand with Adhesive Fingertips for Multimode Grasping and Manipulation.

Soft robotic grippers excel at achieving conformal and reliable contact with objects without the need for complex control algorithms. However, they still lack in grasp and manipulation abilities compared with human hands. In this study, we present a sensorized multi-fingered soft gripper with bioinspired adhesive fingertips that can provide both fingertip-based adhesion grasping and finger-based form closure grasping modes. The gripper incorporates mushroom-like microstructures on its adhesive fingertips, enabling robust adhesion through uniform load shearing. A single fingertip exhibits a maximum load capacity of 4.18 N against a flat substrate. The soft fingers have multiple joints, and each joint can be independently actuated through pneumatic control. This enables diverse bending motions and stable grasping of various objects, with a maximum load capacity of 28.29 N for three fingers. In addition, the soft gripper is equipped with a kirigami-patterned stretchable sensor for motion monitoring and control. We demonstrate the effectiveness of our design by successfully grasping and manipulating a diverse range of objects with varying shapes, sizes, and curvatures. Moreover, we present the practical application of our sensorized soft gripper for remotely controlled cooking.

Biometric analysis hand parameters in young adults for prosthetic hand and ergonomic product applications.

This study aimed to evaluate the superficial anatomy, kinesiology, and functions of the hand to reveal its morphometry and apply the findings in various fields such as prosthetic hand and protective hand support product design. We examined 51 young adults (32 females, 19 males) aged between 18-30. Hand photographs were taken, and measurements were conducted using ImageJ software. Pearson correlation analysis was performed to determine the relationship between personal information and the parameters. The results of the measurements showed the average lengths of finger segments: thumb (49.5±5.5 mm), index finger (63.9±4.1 mm), middle finger (70.7±5.2 mm), ring finger (65.5±4.8 mm), and little finger (53.3±4.3 mm). Both females and males, the left index finger was measured longer than the right index finger. The right ring finger was found to be longer than the left in both sexes. Additionally, length differences between fingers in extended and maximally adducted positions were determined: thumb-index finger (56.1±6.2 mm), index-middle finger (10.7±4.1 mm), middle-ring finger (10.8±1.4 mm), and ring-little finger (25.6±2.7 mm). Other findings included the average radial natural angle (56.4°±10.5°), ulnar natural angle (23.4°±7.1°), radial deviation angle (65.2°±8.2°), ulnar deviation angle (51.2°±9.6°), and grasping/gripping angle (49.1°±5.8°). The average angles between fingers in maximum abduction positions were also measured: thumb-index finger (53.4°±6.5°), index-middle finger (17.2°±2.6°), middle-ring finger (14.3°±2.3°), and ring-little finger (32.1°±7.0°). The study examined the variability in the positioning of proximal interphalangeal joints during maximum metacarpophalangeal and proximal interphalangeal flexion, coinciding with maximum distal interphalangeal extension movements. The focal points of our observations were the asymmetrical and symmetrical arches formed by these joints. This study provides valuable hand parameters in young adults, which can be utilized in various applications such as prosthetic design, ergonomic product development, and hand-related research. The results highlight the significance of considering individual factors when assessing hand morphology and function.

Chemical inhibitors targeting histone methylation readers.

Histone methylation reader domains are protein modules that recognize specific histone methylation marks, such as methylated or unmethylated lysine or arginine residues on histones. These reader proteins play crucial roles in the epigenetic regulation of gene expression, chromatin structure, and DNA damage repair. Dysregulation of these proteins has been linked to various diseases, including cancer, neurodegenerative diseases, and developmental disorders. Therefore, targeting these proteins with chemical inhibitors has emerged as an attractive approach for therapeutic intervention, and significant progress has been made in this area. In this review, we will summarize the development of inhibitors targeting histone methylation readers, including MBT domains, chromodomains, Tudor domains, PWWP domains, PHD fingers, and WD40 repeat domains. For each domain, we will briefly discuss its identification and biological/biochemical functions, and then focus on the discovery of inhibitors tailored to target this domain, summarizing the property and potential application of most inhibitors. We will also discuss the structural basis for the potency and selectivity of these inhibitors, which will aid in further lead generation and optimization. Finally, we will also address the challenges and strategies involved in the development of these inhibitors. It should facilitate the rational design and development of novel chemical scaffolds and new targeting strategies for histone methylation reader domains with the help of this body of data.

Vascular read-out for TRP channel functionality on distal peripheral nerve endings in healthy men.

BACKGROUND: Quantification of the vasodilation after topical application of capsaicin or cinnamaldehyde is often implemented to indirectly assess Transient Receptor Potential (TRP) Vanilloid 1 (TRPV1) or Ankyrin 1 (TRPA1) functionality respectively. This method has been well-established on the human forearm. However, to enable TRP functionality assessments in distal peripheral neuropathy, the vascular response upon TRP activation on dorsal finger skin was characterized. METHODS: Two doses of cinnamaldehyde (3 % and 10 % v/v) and capsaicin (300 µg and 1000 µg) were topically applied (20 µL) on the skin of the mid three proximal phalanges in 17 healthy men. The dose-response, and inter-hand and inter-period reproducibility of the dermal blood flow (DBF) increase was assessed using Laser Speckle Contrast Imaging (LSCI) during 60 min post-application. Linear mixed models explored dose-driven differences, whereas the intra-class correlation coefficient (ICC) estimated the reproducibility of the vascular response. RESULTS: Both doses of cinnamaldehyde and capsaicin induced a robust, dose-dependent increase in DBF. The vascular response to cinnamaldehyde 10 % on finger skin, expressed as area under the curve, correlated well over time (ICC = 0.66) and excellently between hands (ICC = 0.87). Similarly, the response to capsaicin 1000 µg correlated moderately over time (ICC = 0.50) and well between hands (ICC = 0.73). CONCLUSION: The vascular response upon topical cinnamaldehyde and capsaicin application on finger skin is an alternative approach for measurements on forearm skin. Thereby, it is a promising vascular read-out to investigate the pathophysiology, and TRP involvement in particular, of specific peripheral neuropathic pain syndromes.

Primary lymphoma of bone of the little finger: a case report and review of the literature.

Primary lymphoma of bone (PLB) is a rare, malignant lymphoid proliferation within bone accounting for less than 3% of all malignant bone tumors. In this case report, a 61-year-old female with past medical history of gout presented with pain and swelling in her right little finger. Initial radiographs demonstrated periostitis and soft tissue swelling about the right little finger. She returned three months later with progressive pain. Subsequent MRI and repeat radiographs demonstrated near complete destruction of the right little finger middle phalanx and periostitis with marrow infiltration at the right long finger. Given the rapid progression of disease, the differential diagnosis consisted primarily of aggressive neoplastic processes. The little finger ray was amputated through the level of the metacarpophalangeal joint and histopathology demonstrated large neoplastic cells that stained positive with CD45, CD20, and PAX5, compatible with diffuse large B-cell lymphoma. A subsequent normal bone marrow aspiration and PET-CT demonstrated no additional sites of disease, thus excluding secondary lymphoma to bone. To the best of our knowledge, this is the first case report of polyostotic PLB involving the hand. PLB of the hands may be initially misdiagnosed due to its rarity and clinical presentation mimicking rheumatological disease. Clinical vigilance in concert with close imaging follow-up is required to make the diagnosis in a timely fashion. We also review the existing PLB hand literature which consists of five cases.

Research Status and Prospect of Finger Rehabilitation Machinery.

About 80% of stroke patients have hand motor dysfunction, and wearing finger rehabilitation machinery can enable patients to carry out efficient passive rehabilitation training independently. At present, many typical finger rehabilitation machines have been developed, and clinical experiments have confirmed the effectiveness of mechanically assisted finger rehabilitation. In this paper, the finger rehabilitation machinery will be classified in the actuation mode, and the terminal traction drive/motor drive/spring drive/rope drive/memory alloy drive/electroactive material drive/hydraulic drive/pneumatic drive technology and its typical applications are analyzed. Study the structure, control methods, overlap between mechanical bending nodes and finger joints, training modes, response speed, and driving force of various types of finger rehabilitation machinery. The advantages and disadvantages of various actuation methods of finger rehabilitation machinery are summarized. Finally, the difficulties and opportunities faced by the future development of finger rehabilitation machinery are prospected. In general, with the continuous improvement of quality of life, stroke patients need flexible, segmented control, accurate bending, multi-training mode, fast response, and good driving force finger rehabilitation machinery. This will also be a future hot research direction.

A multimodal precision-prevention approach combining lifestyle intervention with metformin repurposing to prevent cognitive impairment and disability: the MET-FINGER randomised controlled trial protocol.

BACKGROUND: Combining multimodal lifestyle interventions and disease-modifying drugs (novel or repurposed) could provide novel precision approaches to prevent cognitive impairment. Metformin is a promising candidate in view of the well-established link between type 2 diabetes (T2D) and Alzheimer's Disease and emerging evidence of its potential neuro-protective effects (e.g. vascular, metabolic, anti-senescence). MET-FINGER aims to test a FINGER 2.0 multimodal intervention, combining an updated FINGER multidomain lifestyle intervention with metformin, where appropriate, in an APOE ε4-enriched population of older adults (60-79 years) at increased risk of dementia. METHODS: MET-FINGER is an international randomised, controlled, parallel-group, phase-IIb proof-of-concept clinical trial, where metformin is included through a trial-within-trial design. 600 participants will be recruited at three sites (UK, Finland, Sweden). Participants at increased risk of dementia based on vascular risk factors and cognitive screening, will be first randomised to the FINGER 2.0 intervention (lifestyle + metformin if eligible; active arm) or to receive regular health advice (control arm). Participants allocated to the FINGER 2.0 intervention group at risk indicators of T2D will be additionally randomised to receive metformin (2000 mg/day or 1000 mg/day) or placebo. The study duration is 2 years. The changes in global cognition (primary outcome, using a Neuropsychological Test Battery), memory, executive function, and processing speed cognitive domains; functional status; lifestyle, vascular, metabolic, and other dementia-related risk factors (secondary outcomes), will be compared between the FINGER 2.0 intervention and the control arm. The feasibility, potential interaction (between-groups differences in healthy lifestyle changes), and disease-modifying effects of the lifestyle-metformin combination will be exploratory outcomes. The lifestyle intervention is adapted from the original FINGER trial (diet, physical activity, cognitive training, monitoring of cardiovascular/metabolic risk factors, social interaction) to be consistently delivered in three countries. Metformin is administered as Glucophage®XR/SR 500, (500 mg oral tablets). The metformin/placebo treatment will be double blinded. CONCLUSION: MET-FINGER is the first trial combining a multimodal lifestyle intervention with a putative repurposed disease-modifying drug for cognitive impairment prevention. Although preliminary, its findings will provide crucial information for innovative precision prevention strategies and form the basis for a larger phase-III trial design and future research in this field. TRIAL REGISTRATION: ClinicalTrials.gov (NCT05109169).

Does Ipsilateral Remapping Following Hand Loss Impact Motor Control of the Intact Hand?

What happens once a cortical territory becomes functionally redundant? We studied changes in brain function and behavior for the remaining hand in humans (male and female) with either a missing hand from birth (one-handers) or due to amputation. Previous studies reported that amputees, but not one-handers, show increased ipsilateral activity in the somatosensory territory of the missing hand (i.e., remapping). We used a complex finger task to explore whether this observed remapping in amputees involves recruiting more neural resources to support the intact hand to meet greater motor control demands. Using basic fMRI analysis, we found that only amputees had more ipsilateral activity when motor demand increased; however, this did not match any noticeable improvement in their behavioral task performance. More advanced multivariate fMRI analyses showed that amputees had stronger and more typical representation-relative to controls' contralateral hand representation-compared with one-handers. This suggests that in amputees, both hand areas work together more collaboratively, potentially reflecting the intact hand's efference copy. One-handers struggled to learn difficult finger configurations, but this did not translate to differences in univariate or multivariate activity relative to controls. Additional white matter analysis provided conclusive evidence that the structural connectivity between the two hand areas did not vary across groups. Together, our results suggest that enhanced activity in the missing hand territory may not reflect intact hand function. Instead, we suggest that plasticity is more restricted than generally assumed and may depend on the availability of homologous pathways acquired early in life.

Prenatal Torsion of Radial Polydactyly: A Gangrenous Mass at the Base of the Thumb.

A patient was born with a mass at the base of the thumb approximately 1.5 cm in diameter on the radial side of the fingers. The mass had globular swelling filled with hemorrhagic fluid and was dark red. X-rays and histology of the excised specimen suggested the diagnosis of gangrene and torsion of polydactyly. Prenatal torsion of polydactyly is not a common occurrence; moreover, prenatal torsion of polydactyly has only been found in ulnar polydactyly. Our case is a novel case of radial polydactyly that was gangrenous at birth owing to prenatal torsion. Diagnosing such a mass at the base of the thumb is important.

High-Resolution Finger MRI: What Should You Look for in Trauma of the Fingers?

The fingers are among the most commonly injured structures in traumatic injuries resulting from sports and work. Finger injuries encompass a broad spectrum of injuries to bone and soft tissues, including tendons, ligaments, and cartilage. The high resolution of 3T MRI with dedicated surface coils allows for optimal assessment of the intricate soft tissue structures of the fingers. There have been several reports on detailed MRI features of the basic anatomy and common pathological findings of the finger and hand. Understanding the normal anatomy and familiarization with common traumatic lesions of the ligaments, tendons, and pulleys of the fingers on high-resolution MRI will allow radiologists to perform accurate preoperative evaluations of traumatic hand lesions. The purpose of this study is to review the normal hand anatomy and common traumatic lesions of the finger on high-resolution MRI and correlate them with surgical findings.

Health-related factors and dysregulation of epigenetic related genes in metabolic syndrome trigger finger patients and smoker trigger finger patients: preliminary analysis of patient-derived sample.

PURPOSE: To investigate the health-related factors and analyze the expression of epigenetic related genes and inflammatory genes in metabolic syndrome Trigger Finger (TF) and smoker TF. METHODS: Samples from patients' fingers with symptomatic TF were collected. There were seven groups: healthy control group, carpal tunnel syndrome (as a control for gene expression analysis), TF, diabetic TF, hypertensive TF, dyslipidemic TF and smoker TF. The expression levels of epigenetic related genes and inflammatory genes in metabolic syndrome TF and smoker TF were evaluated by the reverse transcription-polymerase chain reaction (RT-PCR) technique. The Perceived Stress Scale (PSS), Pittsburgh Sleep Quality Index (PSQI) questionnaires, disability of the arm, shoulder and hand (DASH) and numeric pain rating scale were given to the participants to fill out. RESULTS: There was a significant increase in hand dysfunction in the metabolic TF groups and smoker group compared to the TF group (p < 0.0001). The stress levels of the smoker TF group and TF with hypertension group were significantly increased compared with those in the TF group (p < 0.03) and (p < 0.021), respectively. On the other hand, there was a significant increase in the COL-I, COL-II and TNF-α gene expression of the metabolic TF groups and smoker group (p < 0.0001). CONCLUSIONS: Health-related factors in the TF tendons was highly associated with the level of inflammation and genetic alteration in TF metabolic syndromes and smoker TF patients. Therefore, further investigation is required to examine the combination of occupational therapy, gene expression, and health-related factors as a promising method of managing TF.

Lipoma of the middle finger in an elderly male: A case report.

INTRODUCTION AND IMPORTANCE: Lipomas are common benign tumors originating from adipocytes, often found in adipose-rich regions of the body. Lipomas in the fingers are rare, and their occurrence in acral areas is even more exceptional. We present a case of an elderly male with a lipoma on the middle finger of his left hand, highlighting the rarity of this presentation and the importance of surgical management. CASE PRESENTATION: A 70-year-old male presented with a painless swelling on the palmar aspect of his left middle finger. The mass had gradually enlarged over two years, without associated symptoms. Physical examination revealed a soft, painless mass between the proximal and distal interphalangeal joints, with intact finger function. Surgical excision was performed successfully, and histopathological examination confirmed the diagnosis of a benign lipoma. CLINICAL DISCUSSION: Lipomas are most commonly found in adipose-rich areas but rarely manifest in the fingers. Surgical intervention is considered when symptoms arise or for cosmetic reasons. In this case, the patient's desire for symptom relief and the potential for compression-related issues justified surgical excision. Surgical management of finger lipomas has shown positive outcomes with minimal complications and low recurrence rates. CONCLUSION: This case emphasizes the importance of considering lipomas in the differential diagnosis of painless finger swellings, even in atypical locations. Surgical intervention can provide effective symptom relief and prevent potential complications. While this case contributes to our understanding of finger lipomas, further research and long-term follow-up are needed to enhance our knowledge of these rare occurrences and their management.

Does Surgical Experience Affect the Outcomes During Percutaneous Release of the Trigger Finger?

Background Trigger finger is a condition characterized by clicking or locking during finger movement, sometimes resulting in the freezing of a finger in flexion or extension. The aim of our retrospective study was to determine the effect of the surgeon's learning curve on clinical outcomes in percutaneous release of the trigger finger. In addition, we evaluated the effects of diabetes and local steroid injections on clinical outcomes. Methodology A total of 954 trigger fingers in 678 patients were reviewed from 2012 to 2022. All percutaneous release procedures were performed by a single surgeon in our institute under local anesthesia. The main outcome measures were recurrence and patient satisfaction. In addition, all patients were evaluated in terms of re-operation and complications. The mean follow-up period was 54.87 months. Results There was complete relief of symptoms in 636 (93.81%) patients, and 22 (3.24%) patients had mild pain but were satisfied. We found that the success rate increased over time. The success rate was 91.4% in the first three years and increased to 98.25% in the next seven years (p = 0.001). There was no statistically significant difference between the diabetic and non-diabetic groups in terms of recurrence, satisfaction rate, and complications (p > 0.05). There was no statistically significant difference in terms of recurrence, satisfaction rate, and complications between the groups that received and did not receive steroid injections (p > 0.05). Conclusions Percutaneous release is a safe and reliable procedure in the treatment of trigger fingers, and the success rate increases as the experience increases. Moreover, diabetes mellitus and steroid injections did not affect the clinical results.

The management of trigger fingers: commentary and personal opinion.

Trigger fingers are common. Although the options for management are well-described, including conservative measures such as steroid injection, or surgical options such as open or percutaneous release, there remains variations in the way these are administered. In addition, there is a recent emphasis on patient-reported outcome measures in this condition. The purpose of this further knowledge article is to look at three recently published articles to gather some evidence about best practice in the management of this painful but common condition.

James Walker Dawson: His fingers and their historical context.

Multiple Sclerosis (MS) is one of the most prevalent neurologic disorders in the world. James Walker Dawson examined, in considerable depth, the gross and histologic patterns of MS. Today, periventricular plaques that exhibit an appearance typical for demyelination are nicknamed "Dawson's Fingers." A literature review was conducted on PubMed and Google Scholar to find articles that chronicle the personal and professional life of James Walker Dawson. Research focused on Dawson's work with disseminated sclerosis, or MS as it is known today. Born in India, Dawson and his family moved to Scotland as a child, and he studied at the Edinburgh Institution. After earning his medical degree, Dawson started his career at the Royal College of Physicians of Edinburgh. While his early career focused on the study of wound healing and inflammation, Dawson transitioned into neurologic research under the guidance of Dr. Alexander Bruce in 1908. Dawson's landmark manuscript, "The Histology of Disseminated Sclerosis," published in 1916, featured findings from extensive research on the pathology of MS in nine patients. His findings earned him recognition as a founder of autoimmune neurology and foremost contributor to the current understanding of MS.

The retinacular ligaments of the digital extensor expansion revisited: An anatomical and biomechanical study.

Our aim was to clarify the anatomy and function of the retinacular ligaments. Forty-eight fingers were dissected and the thickness of the oblique retinacular ligament (ORL) was graded. In four fingers, the motion in the proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints was subjected to an in-depth analysis before and after sectioning of either the lateral bands (LB) or the ORLs. The function of the ORLs in restricting flexion of the DIP joint with full extension of the PIP joint was measured in 10 fingers. An ORL could be identified on both sides in all 48 fingers. The distribution of the insertion on the proximal phalanx was 7/96 (7%) in the distal third, 70/96 (73%) in the middle third and 19/96 (20%) in the proximal third. Among the specimens, 29% were graded as having a strong bundle of fibers, 51% as having well-defined and regular fibers and 20% as having thin and sparse fibers. With the PIP joint extended, there was a statistically significant increase in flexion of the DIP joint after the ORL was cut. After the LB was sectioned, the ORL was able to extend the DIP joint with an extension lag of 10-22°. Cutting the ORL did not affect the ability to extend that joint. We conclude that the retinacular ligaments are consistent. Their major role is not connected with finger movement, but to provide stabilizing links between the PIP and DIP joints. They are active in not only specific, uncommon finger positions but also in ordinary use of the fingers.

Pachydermodactyly: Soft Tissue Enlargement of the Fingers in a Teenager.

Pachydermodactyly (PDD) is an uncommon and benign digital fibromatosis of unknown etiology. It is characterized by a fusiform swelling of the medial and lateral sides of the fingers, with unspecific histopathological features of an increased number of fibroblasts, collagen, and mucin deposit in the dermis. Due to its rarity, PDD could be misdiagnosed as rheumatic arthropathies, which could lead to unnecessary immunosuppressant treatments. Here, we report the case of a 16-year-old boy who presented progressive and asymptomatic soft tissue enlargement of multiple fingers in both hands. The histopathological study and X-ray findings correlated with PDD diagnosis. Intralesional corticoid treatment was indicated with a mild improvement.