Helicobacter pylori infection is associated with the development of sporadic colorectal carcinoma and colorectal adenomatous polyps.

Helicobacter pylori (H. pylori) infection is a well-established carcinogen that has been extensively studied in the context of gastric diseases. Recent studies suggested a potential association between H. pylori and the risk of colorectal carcinoma (CRC). However, available data remains insufficient to definitively establish a causal relationship between H. pylori infection and the development of CRC and its precursor lesions. In our study, we reviewed all patients diagnosed with CRC in 2020 at our institution. H. pylori assessment was performed in all 92 CRC specimens by immunohistochemistry. Notably, two of the three patients detected with H. pylori infection are under the age of 50. Subsequently, we reviewed a total of 52 patients under the age of 50 diagnosed with CRC at our institution from 2015 to 2022. Among these patients, H. pylori infection was detected in 7 CRC specimens (13.46 %). All seven patients had adenocarcinoma on the left side of the colon. In exploring the link between H. pylori infection and the risk of developing CRC precursor lesions, we analyzed 242 patients who underwent colonoscopy guided polypectomy and also had stomach biopsies from 2015 to 2022. Of these patients, 21 were proved to be positive for H. pylori infection in the stomach, while the remaining 221 were negative. Among the H. pylori-positive group, 76.19 % (16 patients) exhibited adenomatous polyps, compared to 33.48 % (74 patients) in the H. pylori-negative patients (p=0.0001). However, no H. pylori was detected in any colonic adenomatous polyps. Our findings contribute additional evidence supporting the association between H. pylori infection and the development of sporadic CRC, probably a particular association with early-onset ones. Furthermore, gastric H. pylori infection appears to be linked to the higher prevalence of colonic adenomatous polyps, suggesting that individuals with gastric H. pylori infection may benefit from closer and earlier monitoring through colonoscopy.

Single-Use, Metabolite Absorbing, Resonant Transducer (SMART) Culture Vessels for Label-Free, Continuous Cell Culture Progression Monitoring.

Secreted metabolites are an important class of bio-process analytical technology (PAT) targets that can correlate to cell conditions. However, current strategies for measuring metabolites are limited to discrete measurements, resulting in limited understanding and ability for feedback control strategies. Herein, a continuous metabolite monitoring strategy is demonstrated using a single-use metabolite absorbing resonant transducer (SMART) to correlate with cell growth. Polyacrylate is shown to absorb secreted metabolites from living cells containing hydroxyl and alkenyl groups such as terpenoids, that act as a plasticizer. Upon softening, the polyacrylate irreversibly conformed into engineered voids above a resonant sensor, changing the local permittivity which is interrogated, contact-free, with a vector network analyzer. Compared to sensing using the intrinsic permittivity of cells, the SMART approach yields a 20-fold improvement in sensitivity. Tracking growth of many cell types such as Chinese hamster ovary, HEK293, K562, HeLa, and E. coli cells as well as perturbations in cell proliferation during drug screening assays are demonstrated. The sensor is benchmarked to show continuous measurement over six days, ability to track different growth conditions, selectivity to transducing active cell growth metabolites against other components found in the media, and feasibility to scale out for high throughput campaigns.

Ti3C2Tx MXene reinforcement: a nickel-vanadium selenide/MXene based multi-component composite as a battery-type electrode for supercapacitor applications.

Designing innovative microstructures and implementing efficient multicomponent strategies are still challenging to achieve high-performance and chemo-mechanically stable electrode materials. Herein, a hierarchical three-dimensional (3D) graphene oxide (GO) assisted Ti3C2Tx MXene aerogel foam (MXene-GAF) impregnated with battery-type bimetallic nickel vanadium selenide (NiVSe) has been prepared through a hydrothermal method followed by freeze-drying (denoted as NiVSe-MXene-GAF). 3D-oriented cellular pore networks benefit the energy storage process through the effective lodging of NiVSe particles, improving the access of the electrolyte to the active sites, and alleviating volume changes during redox reactions. The 3D MXene-GAF conductive matrix and heterostructured interface of MXene-rGO and NiVSe facilitated the rapid transport of electrical charges and ions during the charge-discharge process. As a result of the synergism of these effects, NiVSe-MXene-GAF exhibited remarkable electrochemical performance with a specific capacity of 305.8 mA h g-1 at 1 A g-1 and 99.2% initial coulombic efficiency. The NiVSe-MXene-GAF electrode delivered a specific capacity of 235.1 mA h g-1 even at a high current density of 12 A g-1 with a 76.8% rate performance. The impedance measurements indicated a low bulk solution resistance (Rs = 0.71 Ω) for NiVSe-MXene-GAF. Furthermore, the structural robustness of NiVSe-MXene-GAF guaranteed long-term stability with a 91.7% capacity retention for successive 7000 cycles. Thus, developing NiVSe-MXene-GAF provides a progressive strategy for fabricating high-performance 3D heterostructured electrode materials for energy storage applications.

Beyond the ordinary: exploring the synergistic effect of iodine and nickel doping in cobalt hydroxide for superior energy storage applications.

This study explores the iodine and nickel-doped cobalt hydroxide (I & Ni-co-doped-Co(OH)2) as a potential material for energy storage and conversion applications owing to its excellent electrochemical characteristics. According to our analysis, it was revealed that this material exhibits pseudocapacitive-like behavior, as evident from distinct redox peaks observed in cyclic voltammetry, which confirms its ability to store charges. The diffusion coefficient analysis reveals that this material possesses conductivity and rapid diffusion kinetics, making it particularly advantageous compared to materials synthesized in previous studies. Charge-discharge measurements were performed to analyze the charge storage capacity and stability of this material after 3000 consecutive cycles, showing its excellent stability with minimum loss of capacitance. Furthermore, its anodic and cathodic linear sweep voltammetry curves were measured to evaluate its oxygen evolution and hydrogen evolution reaction performance. The results showed that the material exhibited an excellent water splitting performance, which suggests its potential practical application for hydrogen production. This increased activity was attributed to the doping of α-Co(OH)2, which improved its structural stability, electrical conductivity, and charge transfer efficiency. Thus, I & Ni-co-doped-Co(OH)2 possesses enhanced properties that make it an excellent material for both energy storage and hydrogen generation applications.

Three-dimensional bimodal pore-rich G/MXene sponge amalgamated with vanadium diselenide nanosheets as a high-performance electrode for electrochemical water-oxidation/reduction reactions.

Exploring new strategies to design non-precious and efficient electrocatalysts can provide a solution for sluggish electrocatalytic kinetics and sustainable hydrogen energy. Transition metal selenides are potential contenders for bifunctional electrocatalysis owing to their unique layered structure, low band gap, and high intrinsic activities. However, insufficient access to active sites, lethargic water dissociation, and structural degradation of active materials during electrochemical reactions limit their activities, especially in alkaline media. In this article, we report a useful strategy to assemble vanadium diselenide (VSe2) into a 3D MXene/rGO-based sponge-like architecture (VSe2@G/MXe) using hydrothermal and freeze-drying approaches. The 3D hierarchical meso/macro-pore rich sponge-like morphology not only prevents aggregation of VSe2 nanosheets but also offers a kinetics-favorable framework and high robustness to the electrocatalyst. Synergistic coupling of VSe2 and a MXene/rGO matrix yields a heterostructure with a large specific surface area, high conductivity, and multi-dimensional anisotropic pore channels for uninterrupted mass transport and gas diffusion. Consequently, VSe2@G/MXe presented superior electrochemical activity for both the HER and OER compared to its counterparts (VSe2 and VSe2@G), in alkaline media. The overpotentials required to reach a cathodic and anodic current density of 10 mA cm-2 were 153 mV (Tafel slope = 84 mV dec-1) and 241 mV (Tafel slope = 87 mV dec-1), respectively. The Rct values at the open circuit voltage were as low as 9.1 Ω and 1.41 Ω for the HER and OER activity, respectively. Importantly, VSe2@G/MXe withstands a steady current output for a long 24 h operating time. Hence, this work presents a rational design for 3D microstructures with optimum characteristics for efficient bifunctional alkaline water-splitting.

An integrated experimental and theoretical approach to probe Cr(vi) uptake using decorated halloysite nanotubes for efficient water treatment.

Halloysite nanotubes (HNTs) were surface functionalized using four distinct chemical moieties (amidoxime, hydrazone, ethylenediamine (EDA), and diethylenetriamine (DETA)), producing modified HNTs (H1-H4) capable of binding with Cr(vi) ions. Advanced techniques like FTIR, XRD, SEM, and EDX provided evidence of the successful functionalization of these HNTs. Notably, the functionalization occurred on the surface of HNTs, rather than within the interlayer or lumen. These decorated HNTs were effective in capturing Cr(vi) ions at optimized sorption parameters, with adsorption rates ranging between 58-94%, as confirmed by atomic absorption spectroscopy (AAS). The mechanism of adsorption was further scrutinized through the Freundlich and Langmuir isotherms. Langmuir isotherms revealed the nearest fit to the data suggesting the monolayer adsorption of Cr(vi) ions onto the nanotubes, indicating a favorable adsorption process. It was hypothesized that Cr(vi) ions are primarily attracted to the amine groups on the modified nanotubes. Quantum chemical calculations further revealed that HNTs functionalized with hydrazone structures (H2) demonstrated a higher affinity (interaction energy -26.33 kcal mol-1) for the Cr(vi) ions. This can be explained by the formation of stronger hydrogen bonds with the NH moieties of the hydrazone moiety, than those established by the OH of oxime (H1) and longer amine chains (H3 and H4), respectively. Overall, the findings suggest that these decorated HNTs could serve as an effective and cost-efficient solution for treating water pollution.

Vertebral Compression Fracture After Spine Stereotactic Body Radiotherapy: The Role of Vertebral Endplate Disruption.

BACKGROUND AND OBJECTIVES: Vertebral compression fracture (VCF) is a common, but serious toxicity of spinal stereotactic body radiotherapy (SBRT). Several variables that place patients at high risk of VCF have previously been identified, including advanced Spinal Instability Neoplastic Score (SINS), a widely adopted clinical decision criterion to assess spinal instability. We examine the role of tumoral endplate (EP) disruption in the risk of VCF and attempt to incorporate it into a simple risk stratification system. METHODS: This study was a retrospective cohort study from a single institution. Demographic and treatment information was collected for patients who received spinal SBRT between 2013 and 2019. EP disruption was noted on pre-SBRT computed tomography scan. The primary end point of 1-year cumulative incidence of VCF was assessed on follow-up MRI and computed tomography scans at 3-month intervals after treatment. RESULTS: A total of 111 patients were included. The median follow-up was 18 months. Approximately 48 patients (43%) had at least one EP disruption. Twenty patients (18%) experienced a VCF at a median of 5.2 months from SBRT. Patients with at least one EP disruption were more likely to experience VCF than those with no EP disruption (29% vs 6%, P < .001). A nomogram was created using the variables of EP disruption, a SINS of ≥7, and adverse histology. Patients were stratified into groups at low and high risk of VCF, which were associated with 2% and 38% risk of VCF ( P < .001). CONCLUSION: EP disruption is a novel risk factor for VCF in patients who will undergo spinal SBRT. A simple nomogram incorporating EP disruption, adverse histology, and SINS score is effective for quickly assessing risk of VCF. These data require validation in prospective studies and could be helpful in counseling patients regarding VCF risk and referring for prophylactic interventions in high-risk populations.

Iron/vanadium co-doped tungsten oxide nanostructures anchored on graphitic carbon nitride sheets (FeV-WO3@g-C3N4) as a cost-effective novel electrode material for advanced supercapacitor applications.

In this work, we studied the effect of iron (Fe) and vanadium (V) co-doping (Fe/V), and graphitic carbon nitride (g-C3N4) on the performance of tungsten oxide (WO3) based electrodes for supercapacitor applications. The lone pair of electrons on nitrogen can improve the surface polarity of the g-C3N4 electrode material, which may results in multiple binding sites on the surface of electrode for interaction with electrolyte ions. As electrolyte ions interact with g-C3N4, they quickly become entangled with FeV-WO3 nanostructures, and the contact between the electrolyte and the working electrode is strengthened. Herein, FeV-WO3@g-C3N4 is fabricated by a wet chemical approach along with pure WO3 and FeV-WO3. All of the prepared samples i.e., WO3, FeV-WO3, and FeV-WO3@g-C3N4 were characterized by XRD, FTIR, EDS, FESEM, XPS, Raman, and BET techniques. Electrochemical performance is evaluated by cyclic voltammetry (CV), galvanic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS). It is concluded from electrochemical studies that FeV-WO3@g-C3N4 exhibits the highest electrochemical performance with specific capacitance of 1033.68 F g-1 at scan rate 5 mV s-1 in the potential window range from -0.8 to 0.25 V, that is greater than that for WO3 (422.76 F g-1) and FeV-WO3 (669.76 F g-1). FeV-WO3@g-C3N4 has the highest discharge time (867 s) that shows it has greater storage capacity, and its coulombic efficiency is 96.7%, which is greater than that for WO3 (80.1%) and FeV-WO3 (92.1%), respectively. Furthermore, excellent stability up to 2000 cycles is observed in FeV-WO3@g-C3N4. It is revealed from EIS measurements that equivalent series resistance and charge transfer values calculated for FeV-WO3@g-C3N4 are 1.82 Ω and 0.65 Ω, respectively.

Dihydroxyterephthalate-A Trojan Horse PET Counit for Facile Chemical Recycling.

Here, low-energy poly(ethylene terephthalate) (PET) chemical recycling in water: PET copolymers with diethyl 2,5-dihydroxyterephthalate (DHTE) undergo selective hydrolysis at DHTE sites, autocatalyzed by neighboring group participation, is demonstrated. Liberated oligomeric subchains further hydrolyze until only small molecules remain. Poly(ethylene terephthalate-stat-2,5-dihydroxyterephthalate) copolymers were synthesized via melt polycondensation and then hydrolyzed in 150-200 °C water with 0-1 wt% ZnCl2 , or alternatively in simulated sea water. Degradation progress follows pseudo-first order kinetics. With increasing DHTE loading, the rate constant increases monotonically while the thermal activation barrier decreases. The depolymerization products are ethylene glycol, terephthalic acid, 2,5-dihydroxyterephthalic acid, and bis(2-hydroxyethyl) terephthalate dimer, which could be used to regenerate virgin polymer. Composition-optimized copolymers show a decrease of nearly 50% in the Arrhenius activation energy, suggesting a 6-order reduction in depolymerization time under ambient conditions compared to that of PET homopolymer. This study provides new insight to the design of polymers for end-of-life while maintaining key properties like service temperature and mechanical properties. Moreover, this chemical recycling procedure is more environmentally friendly compared to traditional approaches since water is the only needed material, which is green, sustainable, and cheap.

Cranial pilomatricoma: a diagnosis to consider.

Pilomatricomas are benign tumors of the hair follicle that occur frequently in the scalp region. They occur most often in children. We describe a case of pilomatricoma in a teenager, referred to neurosurgery for excision. This diagnosis should be considered in the workup of scalp lesions, and this case report should serve to draw attention to this entity.

Diagnostic errors in musculoskeletal oncology and possible mitigation strategies.

The objective of this paper is to explore sources of diagnostic error in musculoskeletal oncology and potential strategies for mitigating them using case examples. As musculoskeletal tumors are often obvious, the diagnostic errors in musculoskeletal oncology are frequently cognitive. In our experience, the most encountered cognitive biases in musculoskeletal oncologic imaging are as follows: (1) anchoring bias, (2) premature closure, (3) hindsight bias, (4) availability bias, and (5) alliterative bias. Anchoring bias results from failing to adjust an early impression despite receiving additional contrary information. Premature closure is the cognitive equivalent of "satisfaction of search." Hindsight bias occurs when we retrospectively overestimate the likelihood of correctly interpreting the examination prospectively. In availability bias, the radiologist judges the probability of a diagnosis based on which diagnosis is most easily recalled. Finally, alliterative bias occurs when a prior radiologist's impression overly influences the diagnostic thinking of another radiologist on a subsequent exam. In addition to cognitive biases, it is also important for radiologists to acknowledge their feelings when making a diagnosis to recognize positive and negative impact of affect on decision making. While errors decrease with radiologist experience, the lack of application of medical knowledge is often the primary source of error rather than a deficiency of knowledge, emphasizing the need to foster clinical reasoning skills and assist cognition. Possible solutions for reducing error exist at both the individual and the system level and include (1) improvement in knowledge and experience, (2) improvement in clinical reasoning and decision-making skills, and (3) improvement in assisting cognition.

Feasibility, safety, and efficacy of circumferential spine stereotactic body radiotherapy.

Background: With advances in systemic therapy translating to improved survival in metastatic malignancies, spine metastases have become an increasingly common source of morbidity. Achieving durable local control (LC) for patients with circumferential epidural disease can be particularly challenging. Circumferential stereotactic body radiotherapy (SBRT) may offer improved LC for circumferential vertebral and/or epidural metastatic spinal disease, but prospective (and retrospective) data are extremely limited. We sought to evaluate the feasibility, toxicity, and cancer control outcomes with this novel approach to circumferential spinal disease. Methods: We retrospectively identified all circumferential SBRT courses delivered between 2013 and 2019 at a tertiary care institution for post-operative or intact spine metastases. Radiotherapy was delivered to 14-27.5 Gy in one to five fractions. Feasibility was assessed by determining the proportion of plans for which ≥95% planning target volume (PTV) was coverable by ≥95% prescription dose. The primary endpoint was 1-year LC. Factors associated with increased likelihood of local failure (LF) were explored. Acute and chronic toxicity were assessed. Detailed dosimetric data were collected. Results: Fifty-eight patients receiving 64 circumferential SBRT courses were identified (median age 61, KPS ≥70, 57% men). With a median follow-up of 15 months, the 12-month local control was 85% (eight events). Five and three recurrences were in the epidural space and bone, respectively. On multivariate analysis, increased PTV and uncontrolled systemic disease were significantly associated with an increased likelihood of LF; ≥95% PTV was covered by ≥95% prescription dose in 94% of the cases. The rate of new or progressive vertebral compression fracture was 8%. There were no myelitis events or any grade 3+ acute or late toxicities. Conclusions: For patients with circumferential disease, circumferential spine SBRT is feasible and may offer excellent LC without significant toxicity. A prospective evaluation of this approach is warranted.

Cavitation-Mediated Fracture Energy Dissipation in Polylactide at Rubbery Soybean Oil-Based Block Copolymer Interfaces Formed via Reactive Extrusion.

Here, we spearhead a new approach to biopolymer impact modification that demonstrates superior performance while maintaining greater than 99% compostability. Using soybean-based monomers, a virtually untapped resource in terms of commercial volume and overall cost, a series of hyperbranched block copolymers were synthesized and melt-processed with poly(l-lactide) (PLA) to yield impact resistant all-polymer composites. Although PLA impact modification has been treated extensively, to date, the only practical solutions have relied on non-compostable petroleum-based rubbers. This study illustrates the activity of energy dissipation mechanisms such as cavitation, classically relegated to well-entangled petroleum-based rubbers, in poorly entangled hyperbranched soybean-based rubbers. Furthermore, we present a complete study of the mechanical performance and morphology of these impact modified PLA composites. The significance of combining deformation theory with a scalable green alternative to petroleum-based rubbers opens up a potential avenue for cheap compostable engineering thermoplastics.

Spine Stereotactic Body Radiotherapy to Three or More Contiguous Vertebral Levels.

Background: With survival improving in many metastatic malignancies, spine metastases have increasingly become a source of significant morbidity; achieving durable local control (LC) is critical. Stereotactic body radiotherapy (SBRT) may offer improved LC and/or symptom palliation. However, due to setup concerns, SBRT is infrequently offered to patients with ≥3 contiguous involved levels. Because data are limited, we sought to evaluate the feasibility, toxicity, and cancer control outcomes of spine SBRT delivered to ≥3 contiguous levels. Methods: We retrospectively identified all SBRT courses delivered between 2013 and 2019 at a tertiary care institution for postoperative or intact spine metastases. Radiotherapy was delivered to 14-35 Gy in 1-5 fractions. Patients were stratified by whether they received SBRT to 1-2 or ≥3 contiguous levels. The primary endpoint was 1-year LC and was compared between groups. Factors associated with increased likelihood of local failure (LF) were explored. Acute and chronic toxicity was assessed. In-depth dosimetric data were collected. Results: Overall, 165 patients with 194 SBRT courses were identified [54% were men, median age was 61 years, 93% had Karnofsky Performance Status (KPS) ≥70, and median follow-up was 15 months]. One hundred thirteen patients (68%) received treatment to 1-2 and 52 to 3-7 (32%) levels. The 1-year LC was 88% (89% for 1-2 levels vs. 84% for ≥3 levels, p = 0.747). On multivariate analysis, uncontrolled systemic disease was associated with inferior LC for patients with ≥3 treated levels. No other demographic, disease, treatment, or dosimetric variables achieved significance. Rates of new/progressive fracture were equivalent (8% vs. 9.5%, p = 0.839). There were no radiation-induced myelopathy or grade 3+ acute or late toxicities in either group. Coverage of ≥95% of the planning target volume with ≥95% prescription dose was similar between groups (96% 1-2 levels vs. 89% ≥3 levels, p = 0.078). Conclusions: For patients with ≥3 contiguous involved levels, spine SBRT is feasible and may offer excellent LC without significant toxicity. Prospective evaluation is warranted.

Bioenabled Platform to Access Polyamides with Built-In Target Properties.

The diversification of platform chemicals is key to today's petroleum industry. Likewise, the flourishing of tomorrow's biorefineries will rely on molecules with next-generation properties from biomass. Herein, we explore this opportunity with a novel approach to monomers with custom property enhancements. Cyclic diacids with alkyl and aromatic decorations were synthesized from muconic acid by Diels-Alder cycloaddition, and copolymerized with hexamethylenediamine and adipic acid to yield polyamides with built-in hydrophobicity and flame retardancy. Testing shows a 70% reduction in water uptake and doubling of char production while largely retaining other key properties of the parent Nylon-6,6. The present approach can be generalized to access a wide range of performance-advantaged polyamides.

Passivation-driven speciation, dealloying and purification.

Thin passivating surface oxide layers on metal alloys form a dissipation horizon between dissimilar phases, hence harbour an inherent free energy and composition gradient. We exploit this gradient to drive order and selective surface separation (speciation), enabling redox-driven enrichment of the core by selective conversion of low standard reduction potential (E°) components into oxides. Coupling this oxide growth to volumetric changes during solidification allows us to create oxide crystallites trapped in a metal ('ship-in-a-bottle') or extrusion of metal fingerlings on the heavily oxidized particle. We confirm the underlying mechanism through high temperature X-ray diffraction and characterization of solidification-trapped particle states. We demonstrate that engineering the passivating surface oxide can lead to purification via selective dealloying with concomitant enrichment of the core, leading to disparate particle morphologies.

Postoperative Stereotactic Body Radiotherapy for Spinal Metastasis and Predictors of Local Control.

BACKGROUND: Spine surgery is indicated for select patients with mechanical instability, pain, and/or malignant epidural spinal cord compression, with or without neurological compromise. Stereotactic body radiotherapy (SBRT) is an option for durable local control (LC) for metastatic spine disease. OBJECTIVE: To determine factors associated with LC and progression-free survival (PFS) for patients receiving postoperative stereotactic spine radiosurgery. METHODS: We analyzed consecutive patients from 2013 to 2019 treated with surgical intervention followed by SBRT. Surgical interventions included laminectomy and vertebrectomy. SBRT included patients treated with 1 to 5 fractions of radiosurgery. We analyzed LC, PFS, overall survival (OS), and toxicity. Univariate and multivariate analyses were performed. RESULTS: A total of 63 patients were treated with a median follow-up of 12.5 mo. Approximately 75% of patients underwent vertebrectomy and 25% underwent laminectomy. One-year cumulative incidence of local failure was 19%. LC was significantly improved for patients receiving radiosurgery ≤40 d from surgery compared to that for patients receiving radiosurgery ≥40 d from surgery, 94% vs 75%, respectively, at 1 yr (P = .03). Patients who received preoperative embolization had improved LC with 1-yr LC of 88% vs 76% for those who did not receive preoperative embolization (P = .037). Significant predictors for LC on multivariate analysis were time from surgery to radiosurgery, higher radiotherapy dose, and preoperative embolization. The 1-yr PFS and OS was 56% and 60%, respectively. CONCLUSION: Postoperative radiosurgery has excellent and durable LC for spine metastasis. An important consideration when planning postoperative radiosurgery is minimizing delay from surgery to radiosurgery. Preoperative embolization and higher radiotherapy dose were associated with improved LC warranting further study.

Nodular fasciitis on the cheek of a child.

Nodular fasciitis is a benign proliferation of myofibroblastic cells affecting subcutaneous tissue, muscles, and fascia. This rare disorder is most commonly observed on the upper extremity of adults. We present a case of nodular fasciitis of the cheek of a 12-year-old girl.

Polystyrene-block-Polydimethylsiloxane as a Potential Silica Substitute for Polysiloxane Reinforcement.

Here we report microphase-separated poly(styrene-block-dimethylsiloxane) (PS-b-PDMS) as a reinforcing filler in PDMS thermosets that overcomes the long-standing problem of aging in the processing of silica-reinforced silicone. Surprisingly, PS-b-PDMS reinforced composites display comparable mechanical performance to silica-modified analogs, even though the modulus of PS is much smaller than that of silica and there is no evidence of percolation with respect to the rigid PS domains. We have found that a few unique characteristics contribute to the reinforcing performance of PS-b-PDMS. The strong self-assembly behavior promotes batch-to-batch repeatability by having well-dispersed fillers. The structure and size of the fillers depend on the loading and characteristics of both filler and matrix, along with the shear effect. The reinforcing effect of PS-b-PDMS is mostly brought by the entanglements between the corona layer of the filler and the matrix, rather than the hydrodynamic reinforcement of the PS phase.

Thin Biobased Transparent UV-Blocking Coating Enabled by Nanoparticle Self-Assembly.

A waterborne, UV-blocking, and visually transparent nanocomposite coating was formulated with ZnO nanoparticles and 2-hydroxyethyl cellulose (HEC). The coating is highly effective (<5% UV and ∼65% visible transmittance), and the film thickness (0.2-2.5 µm) is ∼100 times thinner than the conventional coatings of similar UV-blocking performance. The superior properties are due to the fractal structures of ZnO nanoparticles assembled within the HEC matrix, revealed by scanning electron microscopy and small-angle X-ray scattering (SAXS). Changing the binder to 2-hydroxyethyl starch (HES) diminishes the UV-blocking performance, as ZnO nanoparticles form dense globular aggregates, with an aggregation number measured by SAXS 3 orders of magnitude larger than the HEC coating. Since HEC and HES share the same repeating glucose unit in the polymer backbone, it suggests that the conformational characteristics of the binder polymer have a strong influence on the nanoparticle aggregation, which plays a key role in determining the optical performance. Similar structures were achieved with TiO2 nanoparticles. This study not only offers a cost-effective and readily scalable method to fabricate transparent UV-blocking coating but also demonstrates that the unique fractal aggregation structures in a nanocomposite material can provide high performance and functionality without fully dispersing the nanoparticles.