Recent strides toward transforming lignin into plastics and aqueous electrolytes for flow batteries.

Lignin is an abundant polyaromatic polymer with a wide range of potential future uses. However, the conversion of lignin into valuable products comes at a cost, and medium- to high-value applications are thus appropriate. Two examples of these are polymers (e.g., as fibers, plasticizers, or additives) and flow batteries (e.g., as redox species). Both of these areas would benefit from lignin-derived molecules with potentially low molecular weight and high (electro)chemical functionality. A promising route to obtain these molecules is oxidative lignin depolymerization, as it enables the formation of targeted compounds with multiple functionalities. An application with high potential in the production of plastics is the synthesis of new sustainable polymers. Employing organic molecules, such as quinones and heterocycles, would constitute an important step toward the sustainability of aqueous flow batteries, and lignin and its derivatives are emerging as redox species, mainly due to their low cost and renewability.

Fully Self-Supervised Out-of-Domain Few-Shot Learning with Masked Autoencoders.

Few-shot learning aims to identify unseen classes with limited labelled data. Recent few-shot learning techniques have shown success in generalizing to unseen classes; however, the performance of these techniques has also been shown to degrade when tested on an out-of-domain setting. Previous work, additionally, has also demonstrated increasing reliance on supervised finetuning in an off-line or online capacity. This paper proposes a novel, fully self-supervised few-shot learning technique (FSS) that utilizes a vision transformer and masked autoencoder. The proposed technique can generalize to out-of-domain classes by finetuning the model in a fully self-supervised method for each episode. We evaluate the proposed technique using three datasets (all out-of-domain). As such, our results show that FSS has an accuracy gain of 1.05%, 0.12%, and 1.28% on the ISIC, EuroSat, and BCCD datasets, respectively, without the use of supervised training.

Techno-economic optimization of a process superstructure for lignin valorization.

Lignin, the most abundant aromatic biopolymer on Earth, is often considered a biorefinery by-product, despite its potential to be valorized into high-added-value chemicals and fuels. In this work, an integrated superstructure-based optimization model was set up and optimized using mixed-integer non-linear programming for the conversion of technical lignin to three main biobased products: aromatic monomers, phenol-formaldehyde resins, and aromatic aldehydes/acids. Several alternative conversion pathways were simultaneously compared to assess the profitability of lignins-based processes by predicting the performance of technologies with different TRL. Upon employing key technologies such as hydrothermal liquefaction, dissolution in solvent, or high-temperature electrolysis, the technical lignins could have a market value of 200 €/t when the market price for aromatic monomers, resins, and vanillin is at least 2.0, 0.8, and 15.0 €/kg, respectively. When lower product selling prices were considered, the aromatic monomers and the resins were not profitable as target products.

On the Oxidative Valorization of Lignin to High-Value Chemicals: A Critical Review of Opportunities and Challenges.

The efficient valorization of lignin is crucial if we are to replace current petroleum-based feedstock and establish more sustainable and competitive lignocellulosic biorefineries. Pulp and paper mills and second-generation biorefineries produce large quantities of low-value technical lignin as a by-product, which is often combusted on-site for energy recovery. This Review focuses on the conversion of technical lignins by oxidative depolymerization employing heterogeneous catalysts. It scrutinizes the current literature describing the use of various heterogeneous catalysts in the oxidative depolymerization of lignin and includes a comparison of the methods, catalyst loadings, reaction media, and types of catalyst applied, as well as the reaction products and yields. Furthermore, current techniques for the determination of product yields and product recovery are discussed. Finally, challenges and suggestions for future approaches are outlined.

Research Progress on the Photo-Driven Catalytic Production of Biodiesel.

Biodiesel considered a green, environmentally friendly, and renewable energy source is one of the most promising candidates to replace fossil fuels to supply energy for the world. The conventional thermocatalytic methods have been extensively explored for producing biodiesel, while inevitably encountering some drawbacks, such as harsh operating conditions and high energy consumption. The catalytic production of biodiesel under mild conditions is a research hotspot but with difficulty. Photocatalysis has recently been highlighted as an eco-friendly and energy-saving approach for biodiesel production. This mini-review summarizes typical photocatalysts for biodiesel production and discusses in detail the catalytic mechanism and strategies of the photo-driven (trans)esterification to produce biodiesel. The current challenges and future opportunities of photo-driven catalysis to prepare biodiesel are also outlined, in steps towards guiding the design of advanced photocatalysts for biodiesel production.

Management of early hepatic artery thrombosis following living-donor liver transplantation: feasibility, efficacy and potential risks of endovascular therapy in the first 48 hours post-transplant-a retrospective cohort study.

This retrospective cohort study aims to review our 18-year experience with early hepatic artery thrombosis (e-HAT) following living-donor liver transplantation (LDLT), as well as to assess the feasibility, efficacy and potential risks of endovascular management of e-HAT in the first 48 hours (hrs) post-LDLT. Medical records of 730 patients who underwent LDLT were retrospectively reviewed. In all cases who had developed e-HAT, treatment modalities employed and their outcomes were evaluated. Thirty-one patients developed e-HAT(4.2%). Definite technical success and 1-year survival rates of surgical revascularization[11/31 cases(35.5%)] were 72.7% & 72.7%, whereas those of endovascular therapy[27/31 cases(87.1%)] were 70.4% & 59.3%, respectively. Endovascular therapy was carried out in the first 48hrs post-transplant in 9/31 cases(29%) [definite technical success:88.9%, 1-year survival:55.6%]. Four procedure-related complications were reported in 3 of those 9 cases(33.3%). In conclusion, post-LDLT e-HAT can be treated by surgical revascularization or endovascular therapy, with comparable results. Endovascular management of e-HAT in the first 48hrs post-LDLT appears to be feasible and effective, but is associated with a relatively higher risk of procedure-related complications, compared to surgical revascularization. Hence, it can be reserved as a second-line therapeutic option in certain situations where surgical revascularization is considered futile, potentially too complex, or potentially more risky.

Spigelian-cryptorchidism syndrome in an adult male complaining of primary infertility: Case report.

History of cryptorchidism is present in about 10% of infertile patients seeking medical help, whereas 20% of them are azoospermic. Most of the patients with bilateral cryptorchidism have a low testicular volume and high serum FSH level. Ectopic testes are present only in 5% of the patients with cryptorchidism. The anterior abdominal wall is a rare site for ectopic testis where Spigelian hernia is usually accompanied. We present a case of bilateral ectopic anterior abdominal wall testes associated with Spigelian hernia on the left side.

Lignin Depolymerization under Continuous-Flow Conditions: Highlights of Recent Developments.

Lignin is a polyaromatic polymer contained in plant cell walls, and it is considered the most abundant noncarbohydrate polymer on Earth. The aromaticity and richness of its functional groups render lignin an attractive starting biomacromolecule for conversion into a variety of value-added products. The development of successful strategies for lignin valorization infers the design of effective depolymerization protocols. Most research on lignin depolymerization has focused on batch-mode processing, whereas only a few studies have investigated such lignin transformations in continuous reactor systems. In this Concept, emerging developments within the concept of continuous lignin processing and the challenges remaining in realizing the efficient valorization of lignin by using this technology are highlighted. A special focus is set on the hydrothermal conversion of technical lignin under continuous-flow conditions, together with suggestions for future research and technology development.

Evaluation of target volume margins for radiotherapy of prostate implanted with fiducial markers.

The planning target volume (PTV) depends on the method of radiotherapy guidance. This study aimed to measure the systemic and random errors using an online marker matching and offline bone structure matching to estimate PTVmarker, PTVbone, or PTVlaser for treatment verification and radiotherapy guidance, especially in centers lacking radiotherapy fiducial markers (FMs). Thirty patients with localized prostate cancer who were treated with FM-based dose escalation protocol were included. The initial set-up was done with laser marks and daily megavoltage images were acquired. The systematic and random errors were calculated. PTVmarker, defined as the sum of maximum marker migration, and PTV calculated to compensate for the difference between online marker matching and offline analysis of marker matching. PTVmarker was added to estimated PTV from online marker matching to obtain PTVlaser. PTVskin marks migration, was calculated and deducted from PTVlaser to acquire PTVbone. The mean maximum marker migration was 2 ± 1.2 mm. The resultant values of PTVmarker were 2.7 ± 0.6 mm, 3.3 ± 1.1 mm, and 4.4 ± 2.2 mm, in the lateral (lat.), longitudinal (long) & vertical (vert.) directions, respectively, whereas values of PTVlaser were 13 ± 0.6 mm, 17.7 ± 1.1 mm, and 15.8 ± 2.2 mm, and PTVbone were 5.9 ± 0.6 mm, 8.6 ± 1.1 mm, 7.2 ± 2.2 mm, respectively, in the lat., long., and vert. directions. Our results show that PTV needed with FM-based image guidance ranged between 3 and 4 mm in the three cardinal directions, was 10 mm smaller than that required with laser skin marks guidance, and narrower by 5 mm compared to that obtained by offline bone structure image matching.

Green solvents-based fractionation process for kraft lignin with controlled dispersity and molecular weight.

The aim of this work is to develop a novel green solvent based sustainable process to refine lignin into low molecular weight (LMW) and high molecular weight (HMW) fractions. Lignin dispersity reduction were experimentally determined using four solvent mixtures, and benchmarked against eight pure solvents. Data outputs were used for modelling the integrated fractionation process. Dispersity reduction of up to 73% was achieved for the high value LMW fraction. Also, a 90% reduction of energy requirement was achieved with an optimized process incorporating a mechanical vapor compression system. This study showed that solvent mixtures involving water can significantly reduce the cost, environment, health and safety impacts of lignin fractionation. Techno-economic evaluation confirmed the economic viability of a large-scale process processing 50 tonne/day of lignin.

Bacterial conversion of depolymerized Kraft lignin.

BACKGROUND: Lignin is a potential feedstock for microbial conversion into various chemicals. However, the microbial degradation rate of native or technical lignin is low, and chemical depolymerization is needed to obtain reasonable conversion rates. In the current study, nine bacterial strains belonging to the Pseudomonas and Rhodococcus genera were evaluated for their ability to grow on alkaline-treated softwood lignin as a sole carbon source. RESULTS: Pseudomonas fluorescens DSM 50090 and Rhodococcus opacus DSM1069 showed the best growth of the tested species on plates with lignin. Further evaluation of P. fluorescens and R. opacus was made in liquid cultivations with depolymerized softwood Kraft lignin (DL) at a concentration of 1 g/L. Size-exclusion chromatography (SEC) showed that R. opacus consumed most of the available lower-molecular weight compounds (approximately 0.1-0.4 kDa) in the DL, but the weight distribution of larger fractions was almost unaffected. Importantly, the consumed compounds included guaiacol-one of the main monomers in the DL. SEC analysis of P. fluorescens culture broth, in contrast, did not show a large conversion of low-molecular weight compounds, and guaiacol remained unconsumed. However, a significant shift in molecular weight distribution towards lower average weights was seen after cultivation with P. fluorescens. CONCLUSIONS: Rhodococcus opacus and P. fluorescens were identified as two potential microbial candidates for the conversion/consumption of base-catalyzed depolymerized lignin, acting on low- and high-molecular weight lignin fragments, respectively. These findings will be of relevance for designing bioconversion of softwood Kraft lignin.

Image-Guided Percutaneous Bleomycin and Bevacizumab Sclerotherapy of Orbital Lymphatic Malformations in Children.

PURPOSE: To evaluate the effectiveness and safety of image-guided percutaneous sclerotherapy using bleomycin for macrocystic and bevacizumab (Avastin™) for microcystic orbital lymphatic malformations in children. MATERIALS AND METHODS: Between October 2015 and July 2018, we prospectively evaluated 10 pediatric patients who presented clinically and radiologically with lymphatic malformations and were treated with percutaneous sclerotherapy. Patients with venous malformations were excluded. Eight females and two males with ages ranging from 3 to 17 years (mean: 8.8, SD: 4.9) were included. Guided with ultrasound and fluoroscopy, macrocysts were treated with bleomycin instillation. For microcystic components in three patients, bevacizumab was injected intralesional. All patients underwent ultrasound and non-contrast MRI to evaluate response to treatment after 6 weeks. RESULTS: The malformations were macrocystic in seven patients and complex (macro/microcystic) in three. Twenty sclerotherapy sessions were performed, (range: 1-3 sessions, mean: 2, SD: 0.8). Clinically, there was a significant reduction in the proptosis after treatment (P = 0.007) and dystopia (P = 0.018). The local radiological response showed a reduction in the maximum lesions diameters and volumes after treatment (P = 0.005 and 0.005, respectively). Two of the three patients treated with bevacizumab showed a reduction in the lesions volumes by 90.4% and 63.4%, respectively, whereas one patient did not show volume reduction. Transient periorbital edema and ecchymosis occurred following the procedure with no major complications encountered. Follow-up ranged from 9-33 months, mean: 20.3, SD: 7.4. CONCLUSION: Bleomycin sclerotherapy is a safe and effective treatment for orbital macrocystic lymphatic malformations. Further use of bevacizumab for microcystic lesions in a larger series is required to outline its efficacy and safety.

The use of diffusion-weighted MR imaging in the functional assessment of the testes of patients with clinical varicocele.

We aimed to evaluate the use of diffusion-weighted imaging (DWI) in the assessment of the varicocele effect on testicular parenchyma and spermatogenesis, with estimation of apparent diffusion coefficient (ADC) value changes in the testicular parenchyma. We prospectively evaluated 30 consecutive patients (18 patients with bilateral varicocele and 12 patients with unilateral varicocele) and 10 healthy controls. US and DWI were performed to all patients. A total of 80 testes were included, which divided into three groups: group A: testes ipsilateral to the varicocele (n = 48, 60%); group B: testes contralateral to the varicocele (n = 12, 15%); and group C: normal testes of the control (n = 20, 25%). There was a statistically significant difference in mean ADC value between all groups (p-value < 0.001). In groups A and B, there was a negative correlation between mean ADC values and varicocele grade as well as pampiniformis venous diameter. In group A, there was a significant positive correlation between mean ADC value and sperm count (p-value = 0.01, r-value = 0.48) as well as sperm motility (p-value = 0.04, r-value = 0.33). DWI sequence can be used to evaluate the sequel of varicocele, with decreased ADC values that are significantly correlated with abnormal semen parameters. Thus, ADC values may be considered as an ancillary indicator of testicular parenchyma changes.

Vision solution for an assisted puncture robotics system positioning.

Medical robotics and computer-assisted surgery are hotspots in the field of robotics and medicine, changing the essence of traditional surgery using a combination of robotic, image processing, and computer technologies. The present paper aimed to study the auxiliary puncture procedure using a robot based on binocular vision optical positioning technology that can be used in minimally invasive surgery for coordinate precision of skin markers. ZED binocular cameras were selected for image acquisition and a model was established based on Zhang's calibration. Moreover, a Hough circle detection algorithm was proposed for binocular stereo image feature extraction to obtain the marker points in three-dimensional space coordinates. Accurate marker coordinate information for a human 3D bone model was obtained, laying the foundation for further research regarding robot-assisted precise positioning technology for use in puncture surgery.

Retraction Note to: Bacterial conversion of depolymerized Kraft lignin.

[This retracts the article DOI: 10.1186/s13068-018-1240-7.].

Bacterial conversion of depolymerized Kraft lignin.

BACKGROUND: Lignin is a potential feedstock for microbial conversion into various chemicals. However, the degradation rate of native or technical lignin is low, and depolymerization is needed to obtain reasonable conversion rates. In the current study, base-catalyzed depolymerization-using NaOH (5 wt%)-of softwood Kraft lignin was conducted in a continuous-flow reactor system at temperatures in the range 190-240 °C and residence times of 1 or 2 min. The ability of growth of nine bacterial strains belonging to the genera Pseudomonas and Rhodococcus was tested using the alkaline-treated lignin as a sole carbon source. RESULTS: Pseudomonas fluorescens and Rhodococcus opacus showed the best growth of the tested species on plates with lignin. Further evaluation of P. fluorescens and R. opacus was made in liquid cultivations with depolymerized lignin (DL) at a concentration of 1 g/L. Size exclusion chromatography (SEC) showed that R. opacus consumed most of the available lower molecular weight compounds (approximately 0.1-0.4 kDa) in the DL, but the weight distribution of larger fractions was almost unaffected. Importantly, the consumed compounds included guaiacol-one of the main monomers in the DL. SEC analysis of P. fluorescens culture broth, in contrast, did not show a large conversion of low molecular weight compounds, and guaiacol remained unconsumed. However, a significant shift in molecular weight distribution towards lower average weights was seen. CONCLUSIONS: Rhodococcus opacus and P. fluorescens were identified as two potential microbial candidates for the conversion/consumption of base-catalyzed depolymerized lignin, acting on low and high molecular weight lignin fragments, respectively. These findings will be of relevance for designing bioconversion of softwood Kraft lignin.

Portal venous pressure and proper graft function in living donor liver transplants in 69 patients from an Egyptian center.

BACKGROUND: Several studies have defined the optimal portal pressure suitable for adequate graft renewal in liver transplantation (LT) but none have studied an Egyptian population to our knowledge. OBJECTIVES: Determine the level of portal venous pressure (PVP) for adequate graft function, and study the effect of PVP modulation on the outcome of LT in an Egyptian population. DESIGN: Cross-sectional, prospectively collected data. SETTING: Liver transplantation unit. PATIENTS AND METHODS: The study included adult cirrhotic pa.tients who underwent right lobe liver donor living transplantation (LDLT) at our transplantation center. Intraoperative Doppler was performed on all LDLT patients. Two PVP measurements were obtained during the recipient operation: before PV clamping and after graft re-perfusion. These PVP measurements were correlated with the results of intraoperative and postoperative Doppler findings and graft function. Mortality in the early postoperative period ( less than 1 month) and development of small-for-size syndrome (SFSS) were recorded. MAIN OUTCOME MEASURES: PVP, graft injury, and the effect of PVP modulation on the outcome of LT were the primary outcome measures. Secondary outcome measures were to correlate PVP to portal vein hemodynamics and intraoperative mean hepatic artery, peak systolic velocity, and also to correlate PVP with the postoperative graft function and mean postoperative platelet count. SAMPLE SIZE AND CHARACTERISTICS: 69 adult patients with end-stage liver disease. RESULTS: Post-reperfusion PVP was lower than pre-clamping PVP. The mean pre-clamping and post-reperfusion values were higher in patients who experienced early mortality and in patients with smaller grafts. A PVP greater than 16.5 mm Hg at the end of the operation predicted the development of SFSS (sensitivity=91.7% and specificity=50.5%). Cases of high PVP that were modulated to a lower level had a smooth and uneventful postoperative outcome. CONCLUSION: PVP is a significant hemodynamic factor that influences the functional status of the transplanted liver, including the development of SFSS, in the Egyptian population. PVP modulation may improve the outcome of LDLT. LIMITATIONS: Further study with a larger sample is needed to confirm these results. CONFLICT OF INTEREST: None.

Early vaccination protects against childhood leukemia: A systematic review and meta-analysis.

Leukemia is the most commonly diagnosed childhood cancer, although its etiology is still largely unknown. Growing evidence supports a role for infection in the etiology of acute lymphocytic leukemia (ALL), and the involvement of the immune system suggests that vaccination may also play a role. However, the findings presented in the published literature are inconsistent. Therefore, we conducted a PRISMA systematic review and meta-analysis. 14 studies were identified and meta-analyzed. Vaccinations studied comprised Bacillus Calmette-Guérin (BCG) vaccine, Triple vaccine, Hepatitis B vaccine (HBV), Polio, Measles, Rubella, Mumps, trivalent MMR vaccine and Haemophilus influenza type B (HiB) vaccine. We observed a protective association between any vaccination in the first year of life and risk of childhood leukemia (summary odds ratio (OR) 0.58 [95% confidence interval (CI) 0.36-0.91]). When individual vaccines were analysed, some evidence of an association was seen only for BCG (summary OR 0.73 [95% CI 0.50-1.08]). In conclusion, early vaccination appears to be associated with a reduced risk of childhood leukemia. This finding may be underpinned by the association observed for BCG. Given the relatively imprecise nature of the results of this meta-analysis, our findings should be interpreted cautiously and replicated in future studies.

A numerical analysis of a magnetocaloric refrigerator with a 16-layer regenerator.

A numerical analysis was conducted to study a room temperature magnetocaloric refrigerator with a 16-layer parallel plates active magnetic regenerator (AMR). Sixteen layers of LaFeMnSiH having different Curie temperatures were employed as magnetocaloric material (MCM) in the regenerator. Measured properties data was used. A transient one dimensional (1D) model was employed, in which a unique numerical method was developed to significantly accelerate the simulation speed of the multi-layer AMR system. As a result, the computation speed of a multi-layer AMR case was very close to the single-layer configuration. The performance of the 16-layer AMR system in different frequencies and utilizations has been investigated using this model. To optimize the layer length distribution of the 16-layer MCMs in the regenerator, a set of 137 simulations with different MCM distributions based on the Design of Experiments (DoE) method was conducted and the results were analyzed. The results show that the 16-layer AMR system can operate up to 84% of Carnot cycle COP at a temperature span of 41 K, which cannot be obtained using an AMR with fewer layers. The DoE results indicate that for a 16-layer AMR system, the uniform distribution is very close to the optimized design.

Biliary Complications in Recipients of Living-Donor Liver Transplant: A Single-Center Review of 120 Patients.

OBJECTIVES: Biliary complications are common after living-donor liver transplant. This retrospective study reviewed our experience with biliary complications in recipients of living-donor liver transplant. MATERIALS AND METHODS: Over our 9-year study period, 120 patients underwent living-donor liver transplant. Patients were divided into 2 groups, with group A having biliary complications and group B without biliary complications. Both groups were compared, and different treatment modalities for biliary complications were evaluated. RESULTS: Group A included 45 patients (37.5%), whereas group B included 75 patients (62.5%). Biliary complications included bile leak in 17 patients (14.2%), biliary stricture in 11 patients (9.2%), combined biliary stricture with bile leak in 15 patients (12.5%), and sphincter of Oddi dysfunction and cholangitis in 1 patient each (0.8%). Cold ischemia time was significantly longer in group A (P = .002). External biliary drainage was less frequently used in group A (P = .031). Technical success rates of endoscopic biliary drainage and percutaneous transhepatic biliary drainage were 68.3% and 41.7%. Survival rate following relaparotomy for biliary complications was 62.5%. CONCLUSIONS: Graft ischemia is an important risk factor for biliary complications. Bile leaks can predispose to anastomotic strictures. The use of external biliary drainage seems to reduce the incidence of biliary complications. Endoscopic and percutaneous trans-hepatic approaches can successfully treat more than two-thirds of biliary complications. Relaparotomy can improve survival outcomes and is usually reserved for patients with intractable biliary complications.