bluuebunny/crossref_metadata_2025 huggingface dataset:
The Diagnostic Value of MRI in Foot and Ankle Surgery
Authors: Tocci Stephen L. , Madom Ian A. , Bradley Michael P. , Langer Phillip R. , DiGiovanni Christopher W.
Published: February 2007

Background: MRI is being used with increasing frequency and seems to have become more popular as a screening tool rather than as an adjunct to narrow specific diagnoses or plan operative interventions. Our hypothesis was that the rising accessibility of this test may be resulting in its overuse. Methods: We retrospectively reviewed 221 consecutive patients referred over a 3-month period for treatment of a lower extremity problem to determine: (1) the number of patients who presented with an MRI already obtained from an outside source, (2) the number of patients who obtained an MRI from the foot and ankle specialist after referral, and (3) the number of times the foot and ankle specialist used these studies or found them helpful in the care of the patient. Fractures (20) were excluded. Results: Of the 201 patients without fractures included in the study, 19.9% (40 of 201) had MRI scans during the course of their treatment; 15.4% (31 of 201) presented to their initial visit with an MRI scan from an outside source, and 4.5% (9 of 201) received MRI scans as ordered by the foot and ankle specialist. Eighty-seven percent (27 of 31) of the pre-referral MRI scans were thought to be unnecessary, and 48.4% (15 of 31) had radiographic interpretations that were considered either immaterial to the patient's pertinent clinical diagnosis or inconsistent with the specialist's interpretations. All nine MRI scans ordered by the specialist were useful in the care of the patient. Therefore, of the 221 consecutive patients, the foot and ankle specialist would have ordered MRI scans in only 5.9% (13 of 221). Conclusions: This study suggests that many of the pre-referral foot or ankle MRI scans obtained before evaluation by a foot and ankle specialist are not necessary. Further studies need to be performed to determine the role of MRI in the screening of foot and ankle disorders.
Midshaft Metatarsal Segmental Osteotomy with Open Reduction and Internal Fixation
Authors: Galluch David B. , Bohay Donald R. , Anderson John G.
Published: February 2007

Background: Metatarsalgia is a common source of patient discomfort and has multiple etiologies. Lesser metatarsal osteotomy is a recognized treatment modality for persistent symptoms after conservative care, yet the location and type of osteotomy remain highly debated topics. The current investigation reports the initial results regarding midshaft, segmental osteotomy of the lesser metatarsals with open reduction and internal fixation. Methods: Ninety-five consecutive patients had lesser metatarsal midshaft, segmental osteotomy with open reduction and internal fixation from June, 1999, to October, 2001, representing 102 feet and 126 osteotomies. Patient records were retrospectively reviewed for osteotomy union, symptomatic relief, and complications associated with this procedure. Followup ranged from 5 months to 18 months with an average of 8.8 months. Fixation was achieved with a four-hole, 1/4-tubular, minifragment, plate and four 2.7-mm cortical screws. Results: Five patients had transfer lesions, (five feet, five osteotomies) within the followup period. One patient (one foot, one osteotomy, 0.8%) developed a nonunion. After hardware removal this patient's osteotomy united. This technique produced excellent metatarsal union rates (125 of 126 osteotomies, 99.2%). Conclusions: Although further clinical investigation regarding patient outcome from this procedure needs to be carried out, the data from this preliminary study indicate that midshaft segmental osteotomy of a lesser metatarsal is a useful technique for metatarsal shortening with a high rate of bony union.
The First Metatarsophalangeal Arc Circumference: Correlation with Angular Measurements
Authors: Piqué-Vidal Carlos
Published: February 2007

Background: The contribution of the different anatomical aspects represented by individual angles to the overall hallux valgus deformity has not been previously examined, and data on the interrelationship of angular measurements are lacking. The objectives of this study were to determine the center of the circle formed by the first metatarsophalangeal arc circumference and to correlate the location of the center with the hallux valgus angle (HVA), the intermetatarsal angle (IMA), the distal metatarsal articular angle (DMAA), and the proximal phalangeal articular angle (PPAA) measurements. Methods: A total of 1933 dorsoplantar weightbearing radiographs of the foot from 1182 patients were analyzed. Measurements evaluated were the IMA, HVA, DMAA, and PPAA. All measurements were performed using a computer program. The arc was defined by the midpoint of the curvature of the medial metaphyseal flare of the hallux proximal phalanx and the proximal and distal metadiaphyseal junctions of the medial border of the hallux. By means of the computer program, the circle's center location was calculated and then outlined according to its position inside or outside of the foot. Results: The smaller the HVA, the larger the circle and the distance between the foot and the center, and vice versa. Similar findings were observed for the DMAA and IMA. Severe hallux valgus deformities (HVA of more than 40 degrees) were associated with location of the center inside the foot. The long radius of the circle was significantly correlated with the HVA values ( p < 0.001). Conclusions: This new approach offers the possibility of summarizing in a single point the correlation of different angular measurements.
Stress Fracture as a Complication of Autogenous Bone Graft Harvest from the Distal Tibia
Authors: Chou Loretta B. , Mann Roger A. , Coughlin Michael J. , III William T. McPeake , Mizel Mark S.
Published: February 2007

Background: Autogenous bone graft from the distal tibia provides cancellous bone graft for foot and ankle operations, and it has osteogenic and osteoconductive properties. The site is in close proximity to the foot and ankle, and published retrospective studies show low morbidity from the procedure. Methods: One-hundred autografts were obtained from the distal tibia between 2000 and 2003. In four cases the distal tibial bone graft harvest resulted in a stress fracture. There were three women and one man. Results: The average time of diagnosis of the stress fracture from the operation was 1.8 months. All stress fractures healed with a short course (average 2.4 months) of cast immobilization. Conclusions: This study demonstrated that a stress fracture from the donor site of autogenous bone graft of the distal tibia occurs and can be successfully treated nonoperatively.
Foot and Ankle Injuries in Elite Female Gymnasts
Authors: Chilvers Margaret , Donahue Michael , Nassar Larry , II Arthur Manoli
Published: February 2007

Background: Gymnastics is a competitive and popular sport that is started at an early age, and elite female gymnasts reach their prime in mid-teenage years. The level of intensity of practice and competition, the number of events, and the degree of difficulty of the maneuvers make gymnastics one of the most injury-producing sports. Methods: Over a 3-year period, 14 elite, female gymnasts were seen in one foot and ankle center. The mean age was 17 (range 14 to 21) years. All gymnasts sustained acute or sub-acute injuries to the foot or ankle requiring surgery. The mechanism of injury, the type of injury, operative repair, and followup were recorded. Results: There were five Lisfranc fracture-dislocations, and five talocalcaneal, two multiple metatarsal, one medial malleolar, one phalangeal, and one sesamoid fracture. All injuries had operative repair. One gymnast with a Lisfranc injury was able to return to full competition; all others with a Lisfranc injury retired from gymnastics, were lost to followup, or graduated from college. One gymnast with a talar osteochondral injury was not able to return to competition but all other injured gymnasts were able to return to gymnastics at the same level or higher. Conclusion: Elite female gymnasts can sustain significant injury to the foot and ankle region. In our study, Lisfranc injuries were most likely career-ending.
Comparative Mechanical Testing of Different Geometric Designs of Distal First Metatarsal Osteotomies
Authors: Vienne Patrick , Favre Phillipe , Meyer Dominik , Schoeniger Ralph , Wirth Stephan , Espinosa Normal
Published: February 2007

Background: The mechanical behavior of a newly described distal metatarsal osteotomy design in the shape of a reversed “L” was compared with the modified chevron and scarf osteotomies. Methods: Experiments were performed using full-sized Sawbone models (Sawbones Europe AB, Malmö, Sweden) of the first ray. Three groups consisting of 10 scarf, 10 modified chevron, and 10 reversed L osteotomies were investigated. All distal fragments were displaced 5 mm laterally without angulation. The proximal fragment of each specimen was embedded in an epoxy resin cylinder and positioned at 15 degrees inclination to the ground. The distal fragment was loaded by a dorsally directed vertical force which was applied at the sesamoid location under the metatarsal head. Load and displacement at failure, work to failure, site of failure and contact areas were recorded for each osteotomy. Results: Similar testing results were obtained in the reversed “L” and chevron osteotomies, while the scarf osteotomy needed almost 5 times less work to failure. In nine of 10 reversed “L” osteotomies and in all scarf osteotomies, the site of failure was at the proximal screw insertion site. The contact areas averaged 163 mm 2 for the reversed “L,” 116 mm 2 for the chevron, and 270 mm 2 for the scarf osteotomy. Conclusions: The reversed L osteotomy is a promising design combining the advantages of both the chevron and scarf osteotomies. Further investigations need to be performed to confirm its clinical utility.
Muscular Lower Leg Asymmetry in Middle-Aged People
Authors: Valderrabano Victor , Nigg Benno M. , Hintermann Beat , Goepfert Beat , Dick Walter , Frank Cyril B. , Herzog Walter , Tscharner Vinzenz von
Published: February 2007

Background: The purpose of this study was to determine whether muscular asymmetries were present in the lower legs of recreationally active middle-aged people grouped by leg dominance. Methods: Twelve healthy middle-aged subjects were analyzed bilaterally. The clinical variables included leg dominance, sports level, range of motion, lower leg alignment, calf circumference, and AOFAS (American Orthopaedic Foot and Ankle Society) ankle score. The biomechanical variables included maximal voluntary isometric ankle joint torque and surface electromyography (EMG) with determination of mean EMG frequency and intensity of four lower leg muscles: anterior tibial (AT), medial gastrocnemius (MG), soleus (SO), and peroneus longus (PL). Results: The mean EMG frequency was significantly lower in the dominant leg for the AT (dominant, 148.6 Hz; nondominant, 157.8 Hz) and MG muscles (dominant, 183.9 Hz; nondominant, 196.8 Hz). A significantly higher plantarflexion torque was found in the dominant leg (27.1 Nm) compared to the nondominant leg (22.9 Nm). Higher (not significant) dorsiflexion torque was found in the dominant leg (dominant, 27.3 Nm; nondominant, 24.8 Nm). The calf circumference was marginally significantly higher ( p = 0.039) in the dominant leg (34.2 cm; nondominant leg, 33.8 cm). The dominant leg had a higher but not significantly different mean EMG intensity for all four muscles. Conclusions and Clinical Relevance: Differences in muscle EMG and torque were found between the dominant and nondominant lower leg. These results might be applicable to treatment, rehabilitation, and future research of lower leg and foot and ankle disorders.
Pressure Changes in the Medial and Lateral Plantar and Tarsal Tunnels Related to Ankle Position: A Cadaver Study
Authors: Barker Allison R. , Rosson Gedge D. , Dellon A. Lee
Published: February 2007

Background: Pressure in the tarsal tunnel has been shown to be elevated when the ankle is pronated. We hypothesized that this also would be true for the medial plantar and lateral plantar tunnels because they also are potential sites of nerve compression. Additionally, we hypothesized that decompression surgery, including a release of the superficial and deep fascia of the abductor hallucis muscle and excision of the septum between the medial and lateral plantar tunnels, would decrease the pressure in all three tunnels. Methods: Twelve fresh cadaver legs were obtained, and pressure measurements were made in a variety of ankle positions in the tarsal and medial and lateral plantar tunnels before and after decompression surgery. For the medial and lateral plantar tunnels, pressures were obtained after tunnel roof (deep fascia of the abductor hallucis) incision and after both roof incision and excision of the septum between the two tunnels. Results: Pressures were significantly elevated in all tunnels with ankle pronation, were significantly decreased in all positions in the tarsal tunnel after decompression, and significantly decreased in most positions in the medial and lateral plantar tunnels after decompression. Septum excision led to additional significant decreases in pressure in some positions. Conclusions: Pressures within the medial and lateral plantar tunnels and the tarsal tunnel increase significantly with changes in ankle subtalar position. These pressure changes can be significantly decreased by operative release of each of these three tunnels, including excision of the septum between the medial and lateral plantar tunnels. Clinical Relevance: Symptoms related to chronic compression of the tibial nerve and its branches at the ankle may be relieved by an operative strategy that targets release of multiple anatomic regions of tightness in the medial ankle rather than focusing on the tarsal tunnel alone.
The “Flap-Shaft” Prosthesis for Insensate Feet with Chopart or Lisfranc Amputations
Authors: Krause Fabian Götz , Aebi Hansjürg , Lehmann Oliver , Weber Martin
Published: February 2007

Background: The inevitable detachment of tendons and the loss of the forefoot in Chopart and Lisfranc amputations result in equinus and varus of the residual foot. In an insensate foot these deformities can lead to keratotic lesions and ulcerations. The currently available prostheses cannot safely counteract the deforming forces and the resulting complications. Methods: A new below-knee prosthesis was developed, combining a soft socket with a rigid shaft. The mold is taken with the foot in the corrected position. After manufacturing the shaft, the lateral third of the circumference of the shaft is cut away and reattached distally with a hinge, creating a lateral flap. By closing this flap the hindfoot is gently levered from the varus position into valgus. Ten patients (seven amputations at the Chopart-level, three amputations at the Lisfranc-level) with insensate feet were fitted with this prosthesis at an average of 3 (range 1.5 to 9) months after amputation. The handling, comfort, time of daily use, mobility, correction of malposition and complications were recorded to the latest followup (average 31 months, range 24 to 37 months after amputation). Results: Eight patients evaluated the handling as easy, two as difficult. No patient felt discomfort in the prosthesis. The average time of daily use was 12 hours, and all patients were able to walk. All varus deformities were corrected in the prosthesis. Sagittal alignment was kept neutral. Complications were two minor skin lesions and one small ulcer, all of which responded to conservative treatment, and one ulcer healed after debridement and lengthening of the Achilles tendon. Conclusions: The “flap-shaft” prosthesis is a valuable option for primary or secondary prosthetic fitting of Chopart-level and Lisfranc-level amputees with insensate feet and flexible equinus and varus deformity at risk for recurrent ulceration. It provided safe and sufficient correction of malpositions and enabled the patients to walk as much as their general condition permitted.
Minimally Invasive Morton's Intermetatarsal Neuroma Decompression
Authors: Zelent Marek E. , Kane Ronald M. , Neese David J. , Lockner William B.
Published: February 2007

Background: We present the results of an alternative technique for decompression of a Morton intermetatarsal neuroma that is minimally invasive and does not require endoscopic instrumentation. Methods: Seventeen nerve decompressions were performed in 14 patients using an instrument designed to release the transverse carpal ligament for carpal tunnel syndrome. Nine women and five men (3 bilateral) had the procedure performed. The mean followup for the 17 decompression procedures was 25.92 months. Results: Eleven of the 14 patients had absence of the neuroma symptoms after the decompression. Two patients had recurrence of symptoms; the third had sustained a crush injury to the operated foot. Both patients with recurrence required revision surgery because the initial procedure failed to relieve symptoms. One patient noted lack of relief in the immediate postoperative period (2 weeks), the other was symptom free for approximately 1 year. Only one of these individuals responded to resection of the intermetatarsal nerve, while the other continues to have pain. There were no wound healing complications or complications related to digital deformity after the procedure. Conclusions: The technique is simple, the postoperative morbidity to the patient is minimal, and the results in this limited number of patients was encouraging.
Digital Redlining—The Invisible Structural Determinant of Health
Authors: Wang Monica L. , Gago Cristina M. , Rodriguez Kate
Published: March 2024

This Viewpoint describes digital redlining as racialized inequities in access to technology infrastructure, including access to health care, education, employment, and social services.
Factors Associated With Use of the Preventive Health Inventory in US Veterans
Authors: Wheat Chelle L. , Wong Edwin S. , Gray Kristen E. , Stockdale Susan E. , Nelson Karin M. , Reddy Ashok
Published: March 2024

Importance

The COVID-19 pandemic caused significant declines in the quality of preventive and chronic disease care. The Veterans Health Administration (VHA) used the Preventive Health Inventory (PHI), a multicomponent care management intervention, to catch up on care disrupted by the pandemic.

Objective

To identify key factors associated with PHI use.

Design, Setting, and Participants

This cohort study of veterans receiving primary care used administrative data from national VHA primary care clinics for February 1, 2021, through February 1, 2022.

Exposure

Patient PHI receipt.

Main Outcomes and Measures

The main outcomes were patient, practitioner, and clinic factors associated with PHI receipt. Binomial generalized linear models with fixed effects for clinic were used to analyze factors associated with receipt of PHI. Least absolute shrinkage and selection operator procedures were used for variable selection.

Results

A total of 4 358 038 veterans (mean [SD] age, 63.7 [16.0] years; 90% male; 76% non-Hispanic White) formed the study cohort, of whom 389 757 (9%) received the PHI. Veterans who received the PHI had higher mean Care Assessment Need (CAN) scores, which indicate the likelihood of hospitalization or death within 1 year (mean [SD], 51.9 [28.6] vs 47.2 [28.6]; standardized mean difference [SMD], −0.16). They were also more likely to live in urban areas (77% vs 64%; SMD, 0.28) and have a shorter drive distance to primary care (mean [SD], 13.2 [12.4] vs 15.7 [14.6] miles; SMD, 0.19). The mean outpatient use was higher among PHI recipients compared with non-PHI recipients (mean [SD], 18.4 [27.8] vs 15.1 [24.1] visits; SMD, −0.13). In addition, veterans with primary care practitioners with higher caseloads were more likely to receive the PHI (mean [SD], 778 [231] vs 744 [249] patients; SMD, −0.14), and they were more likely to be seen at larger clinics (mean [SD], 9670 [6876] vs 8786 [6892] patients; SMD, −0.13). Prior outpatient use and CAN score were associated with PHI receipt in the final model.

Conclusions and Relevance

In this cohort study of the VHA’s PHI, patients with higher CAN scores and more outpatient use in the previous year were more likely to receive the PHI. This study identifies potential intervention points to improve care coordination for veterans.
SGLT2 Inhibitor–Associated Ketoacidosis vs Type 1 Diabetes–Associated Ketoacidosis
Authors: Umapathysivam Mahesh M. , Morgan Bethany , Inglis Joshua M. , Meyer Emily , Liew Danny , Thiruvenkatarajan Venkatesan , Jesudason David
Published: March 2024

This cohort study examines the natural history and response to treatment of sodium glucose cotransporter 2 (SGLT2) inhibitor–associated ketoacidosis compared with that of type 1 diabetes–associated ketoacidosis.
Childhood Overweight and Obesity During and After the COVID-19 Pandemic
Authors: Fäldt Anna , Nejat Sahar , Durbeej Natalie , Holmgren Anton
Published: March 2024

This cohort study analyzes the prevalence of overweight and obesity among preschool children in Sweden before, during, and after the COVID-19 pandemic and longitudinal trends in body mass index.
Estimated Childhood Lead Exposure From Drinking Water in Chicago
Authors: Huynh Benjamin Q. , Chin Elizabeth T. , Kiang Mathew V.
Published: March 2024

Importance

There is no level of lead in drinking water considered to be safe, yet lead service lines are still commonly used in water systems across the US.

Objective

To identify the extent of lead-contaminated drinking water in Chicago, Illinois, and model its impact on children younger than 6 years.

Design, Setting, and Participants

For this cross-sectional study, a retrospective assessment was performed of lead exposure based on household tests collected from January 2016 to September 2023. Tests were obtained from households in Chicago that registered for a free self-administered testing service for lead exposure. Machine learning and microsimulation were used to estimate citywide childhood lead exposure.

Exposure

Lead-contaminated drinking water, measured in parts per billion.

Main Outcomes and Measures

Number of children younger than 6 years exposed to lead-contaminated water.

Results

A total of 38 385 household lead tests were collected. An estimated 68% (95% uncertainty interval, 66%-69%) of children younger than 6 years were exposed to lead-contaminated water, corresponding to 129 000 children (95% uncertainty interval, 128 000-131 000 children). Ten-percentage-point increases in block-level Black and Hispanic populations were associated with 3% (95% CI, 2%-3%) and 6% (95% CI, 5%-7%) decreases in odds of being tested for lead and 4% (95% CI, 3%-6%) and 11% (95% CI, 10%-13%) increases in having lead-contaminated drinking water, respectively.

Conclusions and Relevance

These findings indicate that childhood lead exposure is widespread in Chicago, and racial inequities are present in both testing rates and exposure levels. Machine learning may assist in preliminary screening for lead exposure, and efforts to remediate the effects of environmental racism should involve improving outreach for and access to lead testing services.
A target containing phantom for accuracy assessment of cone‐beam CT‐guided histotripsy
Authors: Kutlu Ayca Z. , Minesinger Grace M. , Laeseke Paul F. , Speidel Michael , Wagner Martin G.
Published: March 2024

Purpose

Histotripsy is a nonionizing, noninvasive, and nonthermal focal tumor therapy. Cone‐beam computed tomography (CBCT) guidance was developed for targeting tumors not visible on ultrasound. This approach assumes cavitation is formed at the geometrical focal point of the therapy transducer. In practice, the exact location might vary slightly between transducers. In this study, we present a phantom with an embedded target to evaluate CBCT‐guided histotripsy accuracy and assess the completeness of treatments.

Methods

Spherical (2.8 cm) targets with alternating layers of agar and radiopaque barium were embedded in larger phantoms with similar layers. The layer geometry was designed so that targets were visible on pre‐treatment CBCT scans. The actual histotripsy treatment zone was visualized via the mixing of adjacent barium and agar layers in post‐treatment CBCT images. CBCT‐guided histotripsy treatments of the targets were performed in six phantoms. Offsets between planned and actual treatment zones were measured and used for calibration refinement. To measure targeting accuracy after calibration refinement, six additional phantoms were treated. In a separate investigation, two groups (N = 3) of phantoms were treated to assess visualization of incomplete treatments (“undertreatment” group: 2 cm treatment within 2.8 cm tumor, “mistarget” group: 2.8 cm treatment intentionally shifted laterally). Treatment zones were segmented (3D Slicer 5.0.3), and the centroid distance between the prescribed target and actual treatment zones was quantified.

Results

In the calibration refinement group, a 2 mm offset in the direction of ultrasound propagation (Z) was measured. After calibration refinement, the centroid‐to‐centroid distance between prescribed and actual treatment volumes was 0.5 ± 0.2 mm. Average difference between the prescribed and measured treatment sizes in the incomplete treatment groups was 0.5 ± 0.7 mm. In the mistarget group, the distance between prescribed and measured shifts was 0.2 ± 0.1 mm.

Conclusion

The proposed prototype phantom allowed for accurate measurement of treatment size and location, and the CBCT visible target provided a simple way to detect misalignments for preliminary quality assurance of CBCT‐guided histotripsy.
The α‐1 Adrenergic Receptor Antagonist Doxazosin Attenuates Liver Fibrosis by Alleviating Sinusoidal Capillarization and Liver Angiogenesis
Authors: Xiu Ai‐Yuan , Ding Qian , Zhu Chang‐Peng , Zhang Chun‐Qing
Published: March 2024

Liver fibrosis and cirrhosis, which are caused by chronic liver injury, represent common and intractable clinical challenges of global importance. However, effective therapeutics are lacking. Therefore, the study examines the effect of doxazosin on liver fibrosis. Carbon tetrachloride (CCl4) is injected into mice to establish a liver fibrosis model. Doxazosin (5 and 10 mg/kg) is administered daily by gavage. HE staining, Masson staining, Sirius Red staining, scanning electron microscopy, western blotting, real‐time PCR, and immunofluorescence analysis are performed to estimate liver fibrosis and sinusoidal capillarization in mice. Cell Counting Kit‐8 assays, western blotting, immunofluorescence analysis, tube formation, and transwell migration assays are performed on human umbilical vein endothelial cells (HUVECs) and human hepatic sinusoidal endothelial cells (HHSECs) to elucidate the potential mechanism of doxazosin. Doxazosin alleviates liver fibrosis and sinusoidal capillarization in CCl4‐induced mice. Angiogenesis is attenuated by doxazosin in HUVECs and HHSECs. This study demonstrates that doxazosin attenuated liver fibrosis by alleviating sinusoidal capillarization and liver angiogenesis.
Preparation of Highly Thermally Conductive Hexagonal Boron Nitride‐Polyvinyl Alcohol/Polydimethylsiloxane Composite Using Combined Freeze‐Drying and Spatial Confining Forced Network Assembly Method
Authors: Li Ning , Qiu Siyuan , Du Qingyuan , An Yi , Chen Yuanmin , Li Yajiao , Wang Wenhao , Wu Daming , Wang Xiaoli , Sun Jingyao
Published: March 2024

With the rapid advancement of electronic products, an increasing number of electronic components are being integrated onto chips, leading to a higher power consumption per unit area. Consequently, effective heat dissipation has become increasingly important. To address this heat dissipation challenge, this article introduces and prepares a highly thermally conductive polymer composite based on freeze‐drying, coupled with the spatial confining forced network assembly (SCFNA) method. The freeze‐drying process is used to create a three‐dimensional thermal conductive network. This network provides a well‐defined heat path. The SCFNA method enhances the regularity of the thermal conductive network within the matrix. Ultimately, this results in the significant thermal conductivity enhancement of the polymer composite. After freeze‐drying, when the mass ratio of hexagonal boron nitride to polyvinyl alcohol is 4:1, the sample prepared by SCFNA presents 72.6% higher thermal conductivity than the one obtained through direct infiltration. This achievement holds significant value for the advancement of polymer composites with high‐thermal conductivity and excellent mechanical properties. It can improve the low‐dissipation performance of polymer thermal conductive composite systems, meet the needs of high‐performance and low‐dissipation use of thermal management materials, and reduce the working temperature of electronic chips.
Infrared Gradient Refractive INdex (GRIN) Materials Through Fast Solid‐Solid Na+/Ag+ Ionic Exchange in Chalco‐Halide Glasses
Authors: Fourmentin Claire , Guichard Jean , Druart Guillaume , Barrière Florence De La , Zhang Xiang‐Hua , Roze Mathieu , Charpentier Frédéric , Proux Raphaël , Guimond Yann , Calvez Laurent
Published: March 2024

In this work, a new two‐step process is developed by exchanging Na+ and Ag+ to create a radial GRIN infrared lens. The first step consists in introducing a high amount of silver by solid‐state ion exchange in the surrounding of the glass sample when the second one allows for controllable diffusion of Ag+ within the center of the sample by single heat treatment. Evolution of the refractive index and ∆n between the two extreme compositions of the GRIN are determined as function of the wavelength, predicting a ∆n of 1.42 × 10−1 at 10 µm. Qualitative characterization of the sample reveals the formation of a GRIN chalcogenide glass transparent in the MWIR and LWIR, presenting no detrimental crystallization of residual metallic silver on the edge of the sample. Wavefront measurement allows to quantitatively characterize the 10 mm diameter IR GRIN as a polynomial profile with a ∆n of 1.8 × 10−1 at 10.6 µm.
Sustainable, Low‐Cost Sorbents Based on Calcium Chloride‐Loaded Polyacrylamide Hydrogels
Authors: Hoogendoorn Levi , Huertas Mauricio , Nitz Phillip , Qi Naiyu , Baller Johannes , Prinz Carsten , Graeber Gustav
Published: March 2024

Sorbents are promising materials for applications in atmospheric water harvesting, thermal energy storage, and passive cooling, thereby addressing central challenges related to water scarcity and the global energy transition. Recently, hygroscopic hydrogel composites have emerged as high‐performance sorbents. However, many of these systems are fabricated with unsustainable and costly sorbent materials, which hinders their wide deployment. Here, the synthesis of high‐performance, cost‐efficient polyacrylamide hydrogels loaded with unprecedented amounts of calcium chloride is demonstrated. To this end, the swelling procedure of polyacrylamide hydrogels in aqueous calcium chloride solutions is optimized. The achievable salt loading in the hydrogel is characterized as a function of temperature, calcium chloride concentration in the swelling solution, and the hydrogel preparation conditions. The obtained hydrogel‐salt composites are shown to be stable under repeated sorption‐desorption cycling and enable water uptakes of 0.92 and 2.38 grams of water per gram of dry materials at 30% and 70% relative humidity, respectively. The resulting cost‐performance ratio substantially exceeds lithium chloride‐based systems. Further, the mechanistic insights on hydrogel salt interactions can guide the design of sustainable and low‐cost sorbent materials for future applications in water and energy.
Extracellular Vesicles Functional “Brick‐Cement” Bio‐Integrated System for Annulus Fibrosus Repair
Authors: Shen Yifan , Pang Libin , Jiang Chao , Jin Jiale , Zhang Yijian , Xing Hongyuan , Li Jiafeng , Wu Honghao , Chen Jingyao , Guan Ming , Zhu Tonghe , Gao Zhongyang , Cui Wenguo , Wang Yue
Published: March 2024

Due to the deficiency of mechanical supporting after discectomy and weak proliferative capacity of annulus fibrosus (AF) cells, the AF defect repair remains a clinical challenge. Herein, a myofibroblasts derived extracellular vesicles (M‐EVs) functional “brick‐cement” bio‐integrated system (M‐EVs@PGBgel) is developed to repair AF defect. The modified Poly(glycerol‐sebacate) (PGBS), “bio‐brick” layer, exhibited excellent support features on account of its elastomeric mechanical properties. The loaded M‐EVs in the “bio‐cement” layer activated ITGA6/PI3K/AKT pathway, regulated M2 macrophage polarization, thus synergistically promoting AF cell proliferation and migration. The “bio‐cement” layer integrated PGBS and remnant tissue at the defect through the Schiff base reaction and aided M‐EVs’ sustained release. This study demonstrated that M‐EVs@PGBgel significantly improved the disc's biological and mechanical properties in the AF defect microenvironments and promoted AF regeneration in vivo. The M‐EVs@PGBgel shows promise as an effective strategy to simultaneously address the mechanical imbalance and biological disruptions resulting from AF defect.
Stability of 2D Crystals from Tessellation
Authors: Huang Haojie , Zhang Ting , Ren Zebin , Ma Yandong , Guo Yunlong , Dong Jichen , Liu Yunqi
Published: March 2024

Reticular chemistry has been a cornerstone in the design of novel 2D materials. Despite numerous possibilities for topological arrangements, only a few with high symmetry can form stable networks. Here, starting from 2D carbons, four types of highly stable tessellations are discovered, which consist of chains of non‐hexagonal rings separated by hexagonal ribbons. A modified Read–Shockley model is established to perfectly describe the stability of these highly stable frameworks, which is based on the interaction between non‐hexagonal rings. Moreover, these four types of tessellations and the modified Read–Shockley model are found to be of general validity in designing highly stable 2D materials, which is verified by the calculations on polymorphs of boron nitride and molybdenum disulfide. Besides, among the studied 2D carbon allotropes, two semi‐metallic structures with highly anisotropic Dirac cones and one semimetal with a Dirac nodal line at the Fermi level are discovered, as protected by their D2h symmetry. Spin‐orbital coupling is further found to open small bandgaps for these three Dirac structures, making them nontrivial topological insulators. The in‐depth understanding of the stability of 2D crystals in this study provides a new way for rational design of 2D crystals that may show peculiar electronic structures.
Rational Design of Bio‐Inspired Peptide Electronic Materials toward Bionanotechnology: Strategies and Applications
Authors: Zhao Jingwen , Liu Qingxi , Tong Xiaoyu , Wang Yuehui , Cai Kaiyong , Ji Wei
Published: March 2024

Biologically inspired peptide‐based materials, as novel charge transport materials, have gained increasing interest in bioelectronics due to their remarkable electrical properties and inherent biocompatibility. Extensive studies have shown that peptides can self‐assemble into a variety of hierarchical nanostructures with unique physical properties through supramolecular interactions. Therefore, peptide‐based materials hold great promise for applications in emerging electronic fields such as sensing, energy harvesting, energy storage, and electronic transmission. Herein, this work proposes a review article to summarize the rational design and research progress of peptide‐based materials and devices in bioelectronics. This work first introduces the design strategies and assembly mechanism for constructing high‐performance peptide‐based electronic materials and devices. In the following part, the applications of peptide‐based electronic materials and devices are systematically classified and discussed, including sensors, piezoelectric nanogenerators, electrodes, and semiconductors. Finally, the remaining challenges and future perspectives of peptide‐based bioelectronic materials and devices are presented. This work believes that this review will provide inspiration and guidance for the design and development of innovative peptide‐based smart materials in the field of bioelectronics.
Adjacent‐Confined Pyrolysis for High‐Density Phase Boundaries in Mo2C Nanosheets to Boost Oxygen Evolution
Authors: Cong Wenhua , Dong Weikang , Yan Yuanyuan , Cao Xun , Xu Yike , Liu Zhenyu , Liu Jijian , Yang Jin , Liu Xuguang , Yang Yang , Fu Longyi , Wang Meiling , Zhang Tianyuan , Zhou Jiadong
Published: March 2024

Heterostructure or doping engineering on Mo2C by coupling with transition metal nanoparticles/atoms can optimize catalytic activities for oxygen evolution reaction (OER). However, the intrinsic catalytic activity of Mo2C is not fully stimulated at the atomic level, which is challenging. Herein, an adjacent‐confined pyrolysis strategy to manipulate the intrinsic electronic structure of Mo2C directly is reported. During the nucleation and growth of Mo2C, the replacement of Mo atoms by adjacent Ni atoms induces the generation of high‐density phase boundaries (PBs) with alternating face‐centered cubic (fcc) and hexagonal close‐packed (hcp) hetero‐phase. The lattice deformity in PBs affords an ultrahigh density of active sites, endowing Mo2C nanosheets with excellent OER activity and superior stability. Theoretical calculations reveal that introduced Ni atoms activate the adjacent Mo sites and optimize the thermodynamic reaction energetics for enhanced OER activity. The work offers a general adjacent‐confined pyrolysis strategy to achieve PBs‐controlling in Mo2C nanosheets for catalytic application and beyond.
Rotational Vortex Metasurface Arrays Enabling Tunable Perfect Petal‐Shaped Beam Emissions
Authors: Chen Meng‐Hsin , Wei Ting‐Yu , Chiang Chia‐Hung , Su Vin‐Cent
Published: March 2024

Actively tunable petal‐shaped pattern emissions have been successfully demonstrated by the cascade of two innovative rotational vortex metasurface arrays (RVMAs). To ensure accurate cascade, each RVMA comprises a central unit with the capability to converge light, surrounded by six units designed for emitting converging vortex beams (VBs) and converging perfect vortex beams (PVBs) with topological numbers (TCs) of 3, 6, and 9, respectively. Notably, although the number of spiral branches and the diameters of the VB and PVB are determined in accordance with specific design TCs, the diameters and the number of petals for the petal‐shaped beam emissions are actively adjusted through the rotation of the RVMAs. Interestingly, the superimposition of these VBs, PVBs, or both, consistently generates petal‐shaped beams with various petal numbers and diameters, highlighting the remarkable versatility of the approach. To demonstrate the proposed concept across wavelengths, indicating its broadband operation capability, RVMA performance in the visible spectrum is thoroughly investigated, ranging from 450 to 600 nm. The tunability of the cascade of RVMAs for petal‐shaped emissions featuring diverse diameters and petal numbers has been validated at visible wavelengths, affirming the broad capabilities of the concept presented in this study.
Tailoring a MOF‐based adsorbent with partitioned aliphatic pore spaces for efficient CH4 purification from natural gas
Authors: Wang Kang , Jiang Yao , Xu Mingming , Zheng Dongdong , Jia Shaojun , Cui Peng
Published: March 2024

Separation of CH4 from natural gas is an essential but extremely challenging process in the petrochemical industry. Here, we tailored a MOF‐based adsorbent with partitioned aliphatic pore spaces through the simultaneous incorporation of the aliphatic sites and the symmetrically matched partition agent. The resulting adsorbent demonstrates exceptional adsorption capacity for C3H8 and C2H6 compared to CH4, along with remarkably competitive adsorption selectivities for C3H8/CH4 and C2H6/CH4. Breakthrough experiments further support the excellent dynamic separation efficiency of the adsorbent for the purification of CH4 from natural gas. Moreover, detailed density functional theory calculations and molecular simulations elucidate the synergistic interactions between the aliphatic sites and the partitioned pore spaces within the adsorbent, which promote the stronger binding affinities for C3H8 and C2H6 over CH4.
WingSegment: A Computer Vision‐Based Hybrid Approach for Insect Wing Image Segmentation and 3D Printing
Authors: Eshghi Shahab , Rajabi Hamed , Poser Johannes , Gorb Stanislav N.
Published: March 2024

This article introduces WingSegment, a MATLAB app‐designed tool employing a hybrid approach of computer vision and graph theory for precise insect wing image segmentation. WingSegment detects cells, junctions, Pterostigma, and venation patterns, measuring geometric features and generating Voronoi patterns. The tool utilizes region‐growing, thinning, and Dijkstra's algorithms for boundary detection, junction identification, and vein path extraction. It provides histograms and box plots of geometric features, facilitating comprehensive wing analysis. WingSegment's efficiency is validated through comparisons with established tools and manual measurements, demonstrating accurate results. The tool further enables exporting detected boundaries as FreeCAD macro files for 3D modeling and printing, supporting finite element analysis. Beyond advancing insect wing morphology understanding, WingSegment holds broader implications for diverse planar structures, including leaves and geocells. This tool not only enhances automated geometric analysis and 3D model generation in insect wing studies but also contributes to the broader advancement of analysis, 3D printing, and modeling technologies across various planar structures.
Metabolic‐Glycoengineering‐Enabled Molecularly Specific Acoustic Tweezing Cytometry for Targeted Mechanical Stimulation of Cell Surface Sialoglycans
Authors: Li Weiping , Guo Jiatong , Hobson Eric C. , Xue Xufeng , Li Qingjiang , Fu Jianping , Deng Cheri X. , Guo Zhongwu
Published: March 2024

In this study, we developed a novel type of dibenzocyclooctyne (DBCO)‐functionalized microbubbles (MBs) and validated their attachment to azide‐labelled sialoglycans on human pluripotent stem cells (hPSCs) generated by metabolic glycoengineering (MGE). This enabled the application of mechanical forces to sialoglycans on hPSCs through molecularly specific acoustic tweezing cytometry (mATC), that is, displacing sialoglycan‐anchored MBs using ultrasound (US). It was shown that subjected to the acoustic radiation forces of US pulses, sialoglycan‐anchored MBs exhibited significantly larger displacements and faster, more complete recovery after each pulse than integrin‐anchored MBs, indicating that sialoglycans are more stretchable and elastic than integrins on hPSCs in response to mechanical force. Furthermore, stimulating sialoglycans on hPSCs using mATC reduced stage‐specific embryonic antigen‐3 (SSEA‐3) and GD3 expression but not OCT4 and SOX2 nuclear localization. Conversely, stimulating integrins decreased OCT4 nuclear localization but not SSEA‐3 and GD3 expression, suggesting that mechanically stimulating sialoglycans and integrins initiated distinctive mechanoresponses during the early stages of hPSC differentiation. Taken together, these results demonstrated that MGE‐enabled mATC uncovered not only different mechanical properties of sialoglycans on hPSCs and integrins but also their different mechanoregulatory impacts on hPSC differentiation, validating MGE‐based mATC as a new, powerful tool for investigating the roles of glycans and other cell surface biomolecules in mechanotransduction.
Stabilizing Lattice Oxygen through Mn Doping in NiCo2O4‐δ Spinel Electrocatalysts for Efficient and Durable Acid Oxygen Evolution
Authors: Zhao Hongyu , Zhu Liu , Yin Jie , Jin Jing , Du Xin , Tan Lei , Peng Yong , Xi Pinxian , Yan Chun‐Hua
Published: March 2024

Design the electrocatalysts without noble metal is still a challenge for oxygen evolution reaction (OER) in acid media. Herein, we reported the manganese (Mn) doping method to decrease the concentration of oxygen vacancy (VO) and form the Mn−O structure adjacent octahedral sites in spinel NiCo2O4‐δ (NiMn1.5Co3O4‐δ), which highly enhanced the activity and stability of spinel NiCo2O4‐δ with a low overpotential (η) of 280 mV at j=10 mA cm−2 and long‐term stability of 80 h in acid media. The isotopic labelling experiment based on differential electrochemical mass spectrometry (DEMS) clearly demonstrated the lattice oxygen in NiMn1.5Co3O4‐δ is more stable due to strong Mn−O bond and shows synergetic adsorbate evolution mechanism (SAEM) for acid OER. Density functional theory (DFT) calculations reveal highly increased oxygen vacancy formation energy (EVO) of NiCo2O4‐δ after Mn doping. More importantly, the highly hydrogen bonding between Mn−O and *OOH adsorbed on adjacent Co octahedral sites promote the formation of *OO from *OOH due to the greatly enhanced charge density of O in Mn substituted sites.
Manipulation of the Self‐Assembly Morphology by Side‐Chain Engineering of Quinoxaline‐Substituted Organic Photothermal Molecules for Highly Efficient Solar‐Thermal Conversion and Applications
Authors: Li Jing , Wang Luoqing , Zhang Chenyang , Wang Han , Pan Yuyu , Li Shizhang , Chen Xian‐Kai , Jia Tao , Wang Kai
Published: March 2024

Organic photothermal materials have attracted increasing attention because of their structural diversity, flexibility, and compatibility. However, their energy conversion efficiency is limited owing to the narrow absorption spectrum, strong reflection/transmittance, and insufficient nonradiative decay. In this study, two quinoxaline‐based D–A‐D–A‐D‐type molecules with ethyl (BQE) or carboxylate (BQC) substituents were synthesized. Strong intramolecular charge transfer provided both molecules with a broad absorption range of 350–1000 nm. In addition, the high reorganization energy and weak molecular packing of BQE resulted in efficient nonradiative decay. More importantly, the self‐assembly of BQE leads to a textured surface and enhances the light‐trapping efficiency with significantly reduced light reflection/transmittance. Consequently, BQE achieved an impressive solar‐thermal conversion efficiency of 18.16 % under 1.0 kW m−2 irradiation with good photobleaching resistance. Based on this knowledge, the water evaporation rate of 1.2 kg m−2 h−1 was attained for the BQE‐based interfacial evaporation device with an efficiency of 83 % under 1.0 kW m−2 simulated sunlight. Finally, the synergetic integration of solar‐steam and thermoelectric co‐generation devices based on BQE was realized without significantly sacrificing solar‐steam efficiency. This underscores the practical applications of BQE‐based technology in effectively harnessing photothermal energy. This study provides new insights into the molecular design for enhancing light‐trapping management by molecular self‐assembly, paving the way for photothermal‐driven applications of organic photothermal materials.