Eugenol Hydrodeoxygenation Over Mixed Mo-W Carbides.

The modification of molybdenum carbide catalysts by another transition metal has raised an increasing research interest due to the significant improvement of catalyst activity in hydrodeoxygenation of lignin derivatives. At par with the commonly used Co and Ni that add a strong hydrogenation functionality, it was found that the addition of the more oxophilic W restricts ring hydrogenation while allowing the deoxygenation of oxygenated compounds and thus yielding higher selectivity toward the formation of non-oxygenated aromatic compounds. The coexistence of Mo2C with W2C along with metallic W altered the electronic properties of Mo2C which resulted in an increase of catalyst active site density and facilitated further total eugenol deoxygenation. Propyl-benzene selectivity of up to 83 % was reached at close to 100 % eugenol conversion. These findings will allow a better overview of the effect of different metal phases of mixed carbides on the catalyst performance and raise the prospect of optimizing catalyst design for a hydrodeoxygenation processing of lignin depolymerization products.

Integrated Sensors for Soft Medical Robotics.

Minimally invasive procedures assisted by soft robots for surgery, diagnostics, and drug delivery have unprecedented benefits over traditional solutions from both patient and surgeon perspectives. However, the translation of such technology into commercialization remains challenging. The lack of perception abilities is one of the obstructive factors paramount for a safe, accurate and efficient robot-assisted intervention. Integrating different types of miniature sensors onto robotic end-effectors is a promising trend to compensate for the perceptual deficiencies in soft robots. For example, haptic feedback with force sensors helps surgeons to control the interaction force at the tool-tissue interface, impedance sensing of tissue electrical properties can be used for tumor detection. The last decade has witnessed significant progress in the development of multimodal sensors built on the advancement in engineering, material science and scalable micromachining technologies. This review article provides a snapshot on common types of integrated sensors for soft medical robots. It covers various sensing mechanisms, examples for practical and clinical applications, standard manufacturing processes, as well as insights on emerging engineering routes for the fabrication of novel and high-performing sensing devices.

Towards a single-use, low-cost endoscope for gastroenterological diagnostics.

Early diagnosis and treatment of diseases in the gastrointestinal (GI) tract including colorectal cancers (CRC) via natural orifices have led to a significant increase in patient survival rates. Most screening procedures utilize image-guided techniques via a conventional endoscope. The cost of conventional endoscopes is substantial, ranging in the tens of thousands of USD or more. This presents significant burden for developing countries, which are disproportionally affected by gastroenterological diseases. Conventional endoscopes also require sterilization between use. This increases the chance of cross-infection between patients. To address these problems, this paper introduces a soft endoscope with a disposable insertion tube that can be articulated. This prototype device is hydraulically actuated, capable of a 10 mm bend radius and 180-degree bend angle. The camera system provides 110 degrees field-of-view. The component parts of this disposable endoscope costs less than 200 USD.Clinical relevance-Our low-cost, single-use endoscope eliminates the sterilization step required by conventional systems, thereby reducing the risks of infection and lowering the operating costs. There is also significant scope for our device to be used beyond the human GI track, such as screening for lung or bladder cancers. Given the compact footprint, the minimal cost of the disposable parts, the proposed platform can widen cancer screening programs with quantifiable economic benefit for many patients, particularly those in developing countries.

A Smart, Textile-Driven, Soft Exosuit for Spinal Assistance.

Work-related musculoskeletal disorders (WMSDs) are often caused by repetitive lifting, making them a significant concern in occupational health. Although wearable assist devices have become the norm for mitigating the risk of back pain, most spinal assist devices still possess a partially rigid structure that impacts the user's comfort and flexibility. This paper addresses this issue by presenting a smart textile-actuated spine assistance robotic exosuit (SARE), which can conform to the back seamlessly without impeding the user's movement and is incredibly lightweight. To detect strain on the spine and to control the smart textile automatically, a soft knitting sensor that utilizes fluid pressure as a sensing element is used. Based on the soft knitting hydraulic sensor, the robotic exosuit can also feature the ability of monitoring and rectifying human posture. The SARE is validated experimentally with human subjects (N = 4). Through wearing the SARE in stoop lifting, the peak electromyography (EMG) signals of the lumbar erector spinae are reduced by 22.8% ± 12 for lifting 5 kg weights and 27.1% ± 14 in empty-handed conditions. Moreover, the integrated EMG decreased by 34.7% ± 11.8 for lifting 5 kg weights and 36% ± 13.3 in empty-handed conditions. In summary, the artificial muscle wearable device represents an anatomical solution to reduce the risk of muscle strain, metabolic energy cost and back pain associated with repetitive lifting tasks.

Transparent Pneumatic Tactile Sensors for Soft Biomedical Robotics.

Palpation is a simple but effective method to distinguish tumors from healthy tissues. The development of miniaturized tactile sensors embedded on endoscopic or robotic devices is key to achieving precise palpation diagnosis and subsequent timely treatment. This paper reports on the fabrication and characterization of a novel tactile sensor with mechanical flexibility and optical transparency that can be easily mounted on soft surgical endoscopes and robotics. By utilizing the pneumatic sensing mechanism, the sensor offers a high sensitivity of 1.25 mbar and negligible hysteresis, enabling the detection of phantom tissues with different stiffnesses ranging from 0 to 2.5 MPa. Our configuration, combining pneumatic sensing and hydraulic actuating, also eliminates electrical wiring from the functional elements located at the robot end-effector, thereby enhancing the system safety. The optical transparency path in the sensors together with its mechanical sensing capability open interesting possibilities in the early detection of solid tumor as well as in the development of all-in-one soft surgical robots that can perform visual/mechanical feedback and optical therapy.

New Halogenated Flavonoids from Adenosma bracteosum and Vitex negundo and Their α-Glucosidase Inhibition.

Adenosma bracteosum and Vitex negundo are natural sources of methoxylated flavonoids. Little is known about the α-glucosidase inhibition of multi-methoxylated flavonoid derivatives. Eighteen natural flavonoids were isolated from A. bracteosum and V. negundo. Seven halogenated derivatives were synthesized. Their chemical structures were elucidated by extensive NMR analysis and high-resolution mass spectroscopy as well as comparisons in literature. All compounds were evaluated for their α-glucosidase inhibition. Most compounds showed good activity with IC50 values ranging from 16.7 to 421.8 µM. 6,8-Dibromocatechin was the most active compound with an IC50 value of 16.7 µM. A molecular docking study was conducted, indicating that those compounds are potent α-glucosidase inhibitors.

Advanced Soft Robotic System for In Situ 3D Bioprinting and Endoscopic Surgery.

Three-dimensional (3D) bioprinting technology offers great potential in the treatment of tissue and organ damage. Conventional approaches generally rely on a large form factor desktop bioprinter to create in vitro 3D living constructs before introducing them into the patient's body, which poses several drawbacks such as surface mismatches, structure damage, and high contamination along with tissue injury due to transport and large open-field surgery. In situ bioprinting inside a living body is a potentially transformational solution as the body serves as an excellent bioreactor. This work introduces a multifunctional and flexible in situ 3D bioprinter (F3DB), which features a high degree of freedom soft printing head integrated into a flexible robotic arm to deliver multilayered biomaterials to internal organs/tissues. The device has a master-slave architecture and is operated by a kinematic inversion model and learning-based controllers. The 3D printing capabilities with different patterns, surfaces, and on a colon phantom are also tested with different composite hydrogels and biomaterials. The F3DB capability to perform endoscopic surgery is further demonstrated with fresh porcine tissue. The new system is expected to bridge a gap in the field of in situ bioprinting and support the future development of advanced endoscopic surgical robots.

Smart textiles using fluid-driven artificial muscle fibers.

The marriage of textiles with artificial muscles to create smart textiles is attracting great attention from the scientific community and industry. Smart textiles offer many benefits including adaptive comfort and high conformity to objects while providing active actuation for desired motion and force. This paper introduces a new class of programmable smart textiles created from different methods of knitting, weaving, and sticking fluid-driven artificial muscle fibers. Mathematical models are developed to describe the elongation-force relationship of the knitting and weaving textile sheets, followed by experiments to validate the model effectiveness. The new smart textiles are highly flexible, conformable, and mechanically programmable, enabling multimodal motions and shape-shifting abilities for use in broader applications. Different prototypes of the smart textiles are created with experimental validations including various shape-changing instances such as elongation (up to 65%), area expansion (108%), radial expansion (25%), and bending motion. The concept of reconfiguring passive conventional fabrics into active structures for bio-inspired shape-morphing structures is also explored. The proposed smart textiles are expected to contribute to the progression of smart wearable devices, haptic systems, bio-inspired soft robotics, and wearable electronics.

A Wearable Soft Fabric Sleeve for Upper Limb Augmentation.

Soft actuators (SAs) have been used in many compliant robotic structure and wearable devices, due to their safe interaction with the wearers. Despite advances, the capability of current SAs is limited by scalability, high hysteresis, and slow responses. In this paper, a new class of soft, scalable, and high-aspect ratio fiber-reinforced hydraulic SAs is introduced. The new SA uses a simple fabrication process of insertion where a hollow elastic rubber tube is directly inserted into a constrained hollow coil, eliminating the need for the manual wrapping of an inextensible fiber around a long elastic structure. To provide high adaptation to the user skin for wearable applications, the new SAs are integrated into flexible fabrics to form a wearable fabric sleeve. To monitor the SA elongation, a soft liquid metal-based fabric piezoresistive sensor is also developed. To capture the nonlinear hysteresis of the SA, a novel asymmetric hysteresis model which only requires five model parameters in its structure is developed and experimentally validated. The new SAs-driven wearable robotic sleeve is scalable, highly flexible, and lightweight. It can also produce a large amount of force of around 23 N per muscle at around 30% elongation, to provide useful assistance to the human upper limbs. Experimental results show that the soft fabric sleeve can augment a user's performance when working against a load, evidenced by a significant reduction on the muscular effort, as monitored by electromyogram (EMG) signals. The performance of the developed SAs, soft fabric sleeve, soft liquid metal fabric sensor, and nonlinear hysteresis model reveal that they can effectively modulate the level of assistance for the wearer. The new technologies obtained from this work can be potentially implemented in emerging assistive applications, such as rehabilitation, defense, and industry.

Size effects on the mechanical behavior and the compressive failure strength of concrete: an extensive dataset.

This data article provides a series of 492 stress-strain curves and compressive strength values obtained under the uniaxial compression of concrete samples fabricated from three different normal-weight concrete mixtures with four different cylindrical sample sizes ranging from 40 × 80 mm to 160 × 320 mm. These data are related to two research articles: "Revisiting statistical size effects on compressive failure of heterogeneous materials, with a special focus on concrete" (Vu et al., 2018) [1] and "Revisiting the concept of characteristic compressive strength of concrete" (Vu et al., 2020) [2]. In those papers, the strength values were used to (i) analyze and interpret statistical size effects on compressive strength of concrete (in ref. [1]), and (ii) discuss and evaluate the genuine characteristic compressive strength of concrete when size effects on strength are taken into account (in ref. [2]). This dataset could be reused for other statistical analyses on the mechanical behavior of concrete (e.g. elastic and strength properties) and associated possible mixture or size effects. In addition, the characteristic properties of the hardened concrete samples such as the apparent density, the moisture content, the modulus of elasticity as well as the internal microstructures are also provided.

Asymmetric Damage Avalanche Shape in Quasibrittle Materials and Subavalanche (Aftershock) Clusters.

Crackling dynamics is characterized by a release of incoming energy through intermittent avalanches. The shape, i.e., the internal temporal structure of these avalanches, gives insightful information about the physical processes involved. It was experimentally shown recently that progressive damage toward compressive failure of quasibrittle materials can be mapped onto the universality class of interface depinning when considering scaling relationships between the global characteristics of the microcracking avalanches. Here we show, for three concrete materials and from a detailed analysis of the acoustic emission waveforms generated by microcracking events, that the shape of these damage avalanches is strongly asymmetric, characterized by a very slow decay. This remarkable asymmetry, at odds with mean-field depinning predictions, could be explained, in these quasibrittle materials, by retardation effects induced by enhanced viscoelastic processes within a fracture process zone generated by the damage avalanche as it progresses. It is associated with clusters of subavalanches, or aftershocks, within the main avalanche.

Endovascular Treatment for Acute Tandem Occlusion Stroke: Results from Case Series of 17 Patients.

BACKGROUND AND PURPOSE: Tandem occlusive lesion, a major challenge for thrombectomy in acute anterior circulation strokes, is poorly represented in randomized trials. This study demonstrates the findings of thrombectomy in tandem occlusion and comparative analysis of two treatment groups (extracranial versus intracranial first subgroup). PATIENTS AND METHODS: We enrolled and divided 17 patients with acute tandem ischemic stroke who received endovascular treatment into two groups. Group 1 with completed (100%) internal carotid artery (ICA) occlusion was treated by an extracranial stent, whereas Group 2 with severe (70%-99%) ICA occlusion was prioritized with intracranial thrombectomy. Data of clinical parameters, imaging and angiographic results, periprocedural complications, and results after 3 months were collected and analyzed. RESULTS: The mean age of patients was 70.2 ± 8.8 years, and males accounted for 94.1%. The National Institutes of Health Stroke Scale and Alberta Stroke Program Early CT Score (ASPECTS) baseline were 16.6 ± 4.2 and 7.6 ± 1.1, respectively, with occlusive side was 52.9% on the right. Group 1 including ten cases (58.8%) was treated extracranial lesion with carotid stent before intracranial thrombectomy, and Group 2 with seven cases (41.2%) was prioritized intracranial thrombectomy. In total 17 procedures, there were ten stent retrievers (58.8%), four aspirations (23.5%), and three Solumbra (17.7%). No re-occlusion of carotid stent postoperation was recorded. The good revascularization (thrombolysis in cerebral infarction 2b-3) was archived in 82.4% of patients, while symptomatic hemorrhage was seen in 2 cases (11.8%). Three months after treatment, patients with favorable clinical outcome (Modified Rankin Scale ≤2) accounted for 47.1%. CONCLUSION: Our study determined a promising outcome with reasonable good recanalization and clinical recovery for endovascular intervention in tandem ischemic. In the subgroup of treatment, "extracranial stent first" had more complex disease with completed ICA occlusion which required longer procedure time may lead to worse outcome.

Compressive Failure as a Critical Transition: Experimental Evidence and Mapping onto the Universality Class of Depinning.

Acoustic emission (AE) measurements performed during the compressive loading of concrete samples with three different microstructures (aggregate sizes and porosity) and four sample sizes revealed that failure is preceded by an acceleration of the rate of fracturing events, power law distributions of AE energies and durations near failure, and a divergence of the fracturing correlation length and time towards failure. This argues for an interpretation of compressive failure of disordered materials as a critical transition between an intact and a failed state. The associated critical exponents were found to be independent of sample size and microstructural disorder and close to mean-field depinning values. Although compressive failure differs from classical depinning in several respects, including the nature of the elastic redistribution kernel, an analogy between the two processes allows deriving (finite-) sizing effects on strength that match our extensive data set. This critical interpretation of failure may have also important consequences in terms of natural hazards forecasting, such as volcanic eruptions, landslides, or cliff collapses.

Bilateral blindness with secondary retinitis pigmentosa following postoperative docetaxel and platinum combination chemotherapy in primary small-cell carcinoma of the endometrium: An unusual case report and review of the literature.

Ocular toxicity is an uncommon complication of cytotoxic chemotherapy. Bilateral blindness with secondary retinitis pigmentosa (RP) following docetaxel and platinum combination chemotherapy at the recommended dose is extremely rare. The present study reports a case of advanced small-cell carcinoma (SCC) of the endometrium in a patient with diabetes mellitus type 2. The patient suffered from RP with a sharp decline in vision after the fourth course of postoperative docetaxel and platinum combination chemotherapy. Unfortunately, the patient developed bilateral blindness after another course of chemotherapy at a reduced dose. No tumor recurrence was observed during the 33 months of follow-up. A total of 35 cases of docetaxel- and/or platinum-induced retinal toxicity were found in the English literature and reviewed. The ischemic and electrophysiological hypotheses may have been implicated in the pathogenesis of ocular toxicity in the present case, particularly with the history of diabetes. Understanding the ocular side effects of this combination chemotherapy may assist gynecological oncologists and ophthalmologists with early recognition and timely intervention before blindness is established.

Does HBV infection increase risk of endometrial carcinoma?

OBJECTIVE: Connections between chronic inflammation and tumor development and progression are now generally accepted. Recent evidence indicates that hepatitis B is associated with several types of cancer, but whether endometrial carcinoma (EC) is included has not been reported. METHODS: We analyzed HBV serum marker status in 398 patients with endometrial cancer, comparing them to 788 control women undergoing health examination. RESULTS: The total prevalence of HBsAg tested positive in cancer group was significantly higher than the control group (12.8% vs 6.0%, P=0.001), while positive HBsAb was significantly lower (41.2% vs 68.5%, P=0.001). Hepatitis B carriers in endometrial cancer group were also more frequent than in the control group (9.3% vs 5.5%, P=0.013). Interestingly, in the endometrial cancer group, 147 cases were HBV serum marker negative, which was also higher than in the control group (36.9% vs 15.6%, P=0.001). CONCLUSION: There may be a correlation between HBV infection and endometrial carcinoma.

[Rapid determination of sugars in hemicellulose extraction liquor by dual-wavelength spectrophotometry].

The traditional Douglas colorimetric method (phloroglucinol - glacial acetic acid colorimetry) could only be used to measure all forms of five-carbon sugars, including mono-, oligo- and poly- saccharides. Relative improvement is done on this method to achieve simultaneous determination of pentosan, hexosan and their monosaccharides, by the dual-wavelength method. Results indicate that 425 nm is the equal molar absorption wavelength of pentose and hexose, while 553 nm is the maximum absorption wavelength of pentoses. So the calculating formula has been greatly simplified based on the absorbance at 425 and 553 nm. The research results of interfering substances in the extraction liquor show that the lignin and glucuronic acid has no significant influence on the determination of pentoses or hexoses. It is concluded that this improved method has high precision and accuracy, and its recovery range is from 97.4% to 101.9%. Therefore, as a simple and rapid method, it is quite appropriate for measuring mixed sugars of pentoses and hexoses in the extraction liquor from hardwood or gra minaceous plant.