Enhancing biomass conversion to bioenergy with machine learning: Gains and problems.

The growing concerns about environmental sustainability and energy security, such as exhaustion of traditional fossil fuels and global carbon footprint growth have led to an increasing interest in alternative energy sources, especially bioenergy. Recently, numerous scenarios have been proposed regarding the use of bioenergy from different sources in the future energy systems. In this regard, one of the biggest challenges for scientists is managing, modeling, decision-making, and future forecasting of bioenergy systems. The development of machine learning (ML) techniques can provide new opportunities for modeling, optimizing and managing the production, consumption and environmental effects of bioenergy. However, researchers in bioenergy fields have not widely utilized the ML concepts and practices. Therefore, a comparative review of the current ML techniques used for bioenergy productions is presented in this paper. This review summarizes the common issues and difficulties existing in integrating ML with bioenergy studies, and discusses and proposes the possible solutions. Additionally, a detailed discussion of the appropriate ML application scenarios is also conducted in every sector of the entire bioenergy chain. This indicates the modernized conversion processes supported by ML techniques are imperative to accurately capture process-level subtleties, and thus improving techno-economic resilience and socio-ecological integrity of bioenergy production. All the efforts are believed to help in sustainable bioenergy production with ML technologies for the future.

Regulating the Chiroptical Expression of Aggregated Solvophobic Core by Solvophilic Segments.

The investigation of chiral supramolecular stacking is of essential significance for the understanding of the origin of homochirality in nature. Unlike structurally well-defined amphiphilic liposomes, it remains unclear whether the solvophilic segments of the amphiphilic block copolymer play a decisive role in the construction of asymmetric superstructures. Herein, insights are presented into the stacking patterns and morphological regulation in azobenzene-containing block copolymer assemblies solely by modulating the solvophilic chain length. The solvophilic poly(methacrylic acid) (PMAA) segments of different molecular weights could cause multi-mode chirality inversions involving stacking transitions between intra-chain π-π stacking, inter-chain H- and J-aggregation. Furthermore, the length of the solvophilic PMAA also affects the morphology of the chiral supramolecular assemblies; rice grain-like micelles, worms, nanofibers, floccules, and lamellae can be prepared at different solvophilic-solvophobic balance. The comprehensive mechanism is collectively revealed by utilizing various measurement methods, such as including circular dichroism (CD), small-angle X-ray scattering (SAXS), and wide-angle X-ray diffraction (WAXD). This study highlights the critical importance of fully dissolved solvophilic segments for the chiroptical regulation of the aggregated core, providing new insights into the arrangement of chiral supramolecular structures in polymer systems.

Precise Modulation of Circularly Polarized Luminescence via Polymer Chiral Co-assembly and Contactless Dynamic Chiral Communication.

Circularly polarized luminescence (CPL) plays a pivotal role in cutting-edge display and information technologies. Currently achieving precise color control and dynamic signal regulation in CPL still remains challenging due to the elusory relationship between fluorescence and chirality. Inspired by the natural mechanisms governing color formation and chiral interaction, we proposed an addition-subtraction principle theory to address this issue. Three fluorene-based polymers synthesized by Suzuki polycondensation with different electron-deficient monomers exhibit similar structures and UV/Vis absorption, but distinct fluorescence emissions due to intramolecular charge transfer. Based on this, precise-color CPL-active films are obtained through quantitative supramolecular co-assembly directed by addition principle. Particularly, an ideal white-emitting CPL film (CIE coordinates: (0.33, 0.33)) is facilely fabricated with a high quantum yield of 80.8 % and a dissymmetry factor (glum) of 1.4×10-2. Structural analysis reveals that the ordered stacking orientation favors higher glum. Furthermore, to address the dynamically regulated challenge, the comparable subtraction principle is proposed, involving a contactless chiral communication between excited and ground states. The representative system consisting of as-prepared fluorene-based polymers and chirality-selective absorption azobenzene (Azo)-containing polymers is constructed, achieving CPL weakening, reversal, and enhancement. Finally, a switchable quick response code is realized based on trans-cis isomerization of Azo moiety.

Revealing Pathway Complexity and Helical Inversion in Supramolecular Assemblies Through Solvent-Induced Radical Disparities.

New insights are raised to interpret pathway complexity in the supramolecular assembly of chiral triarylamine tris-amide (TATA) monomer. In cosolvent systems, the monomer undergoes entirely different assembly processes depending on the chemical feature of the two solvents. Specifically, 1,2-dichloroethane (DCE) and methylcyclohexane (MCH) cosolvent trigger the cooperative growth of monomers with M helical arrangement, and hierarchical thin nanobelts are further formed. But in DCE and hexane (HE) combination, a different pathway occurs where monomers go through isodesmic growth to generate twisted nanofibers with P helical arrangement. Moreover, the two distinct assemblies exhibit opposite excited-state chirality. The driving force for both assemblies is the formation of intermolecular hydrogen bonds between amide moieties. However, the mechanistic investigation indicates that radical and neutral triarylamine species go through distinct assembly phases by changing solvent structures. The neutralization of radicals in MCH plays a critical role in pathway complexity, which significantly impacts the overall supramolecular assembly process, giving rise to inversed supramolecular helicity and distinct morphologies. This differentiation in pathways affected by radicals provides a new approach to manipulate chiral supramolecular assembly process by facile solvent-solute interactions.

Aeration-Free In Situ Fenton-like Reaction: Specific Adsorption and Activation of Oxygen on Heterophase Oxygen Vacancies.

Aeration accounts for 35-51% of the overall energy consumption in wastewater treatment processes and results in an annual energy consumption of 5-7.5 billion kWh. Herein, a solar-powered continuous-flow device was designed for aeration-free in situ Fenton-like reactions to treat wastewater. This system is based on the combination of TiO2-x/W18O49 featuring heterophase oxygen vacancy interactions with floating reduced graphene/polyurethane foam, which produces hydrogen peroxide in situ at the rates of up to 4.2 ppm h-1 with degradation rates of more than 90% for various antibiotics. The heterophase oxygen vacancies play an important role in the stretching of the O-O bond by regulating the d-band center of TiO2-x/W18O49, promoting the hydrogenation of *·O2- or *OOH by H+ enrichment, and accelerating the production of reactive oxygen species by spontaneous adsorption of hydrogen peroxide. Furthermore, the degradation mechanisms of antibiotics and the treatment of actual wastewater were thoroughly investigated. In short, the study provides a meaningful reference for potentially undertaking the "aeration-free" in situ Fenton reaction, which can help reduce or even completely eradicate the aeration costs and energy requirements during the treatment of wastewater.

Simultaneous Chiral Fixation and Chiral Regulation Endowed by Dynamic Covalent Bonds.

The construction of chiral superstructures through the self-assembly of non-chiral polymers usually relies on the interplay of multiple non-covalent bonds, which is significantly limited by the memory ability of induced chirality. Although the introduction of covalent crosslinking can undoubtedly enhance the stability of chiral superstructures, the concurrent strong constraining effect hinders the application of chirality-smart materials. To address this issue, we have made a first attempt at the reversible fixation of supramolecular chirality by introducing dynamic covalent crosslinking into the chiral self-assembly of side-chain polymers. After chiral induction, the reversible [2+2] cycloaddition reaction of the cinnamate group in the polymer chains can be further controlled by light to manipulate inter-chain crosslinking and decrosslinking. Based on this photo-programmable and dynamic chiral fixation strategy, a novel pattern-embedded storage mechanism of chiral polymeric materials was established for the first time.

Rational design of recyclable metal-organic frameworks-based materials for water purification: An opportunity for practical application.

Due to their high specific surface area (SSA), numerous active sites, and customizable pore structure, metal-organic frameworks (MOFs) have emerged as a popular topic in wastewater treatment research. Unfortunately, MOFs exist in the form of powder, which poses significant challenges such as difficult recycling and powder contamination in practical applications. Accordingly, for solid-liquid separation, the strategies of endowing magnetism and constructing appropriate device architectures are important. This review offers a detailed overview of the preparation strategies for recyclable MOFs-based magnetism and device materials and introduces the characteristics of these preparation methods through relevant instances. Besides, these two recyclable materials' applications and working mechanisms for removing pollutants from water through adsorption, advanced oxidation, and membrane separation technologies are introduced. The findings presented in this review will provide a valuable reference for the preparation of MOFs-based materials with excellent recyclability.

Self-recovery of chiral microphase separation in an achiral diblock copolymer system.

Macroscopic regulation of chiral supramolecular nanostructures in liquid-crystalline block copolymers is of great significance in photonics and nanotechnology. Although fabricating helical phase structures via chiral doping and microphase separation has been widely reported, the chiral memory and self-recovery capacity of asymmetric phase structures are the major challenge and still deeply rely on the presence of chiral additives. Herein, we demonstrate the first controllable chiral microphase separation in an achiral amphiphilic block copolymer consisting of poly(ethylene oxide) and azobenzene (Azo) groups. Chirality can be transferred to the fabricated helical nanostructures by doping with chiral additives (tartaric acid, TA). After the removal of the chiral additives and then performing cross-linking, the formed helical nanostructures will completely dispense with the chiral source. The supramolecular chirality and the micron-scale phase structure can be maintained under UV irradiation and heating-cooling treatment, enabling a reversible "on-off" chiroptical switch feature. This work is expected to avoid the tedious synthesis and expensive raw materials and shows a great application prospect in chiral separation and so on.

Enhancing Biochar-Based Nonradical Persulfate Activation Using Data-Driven Techniques.

Converting biomass into biochar (BC) as a functional biocatalyst to accelerate persulfate activation for water remediation has attracted much attention. However, due to the complex structure of BC and the difficulty in identifying the intrinsic active sites, it is essential to understand the link between various properties of BC and the corresponding mechanisms promoting nonradicals. Machine learning (ML) recently demonstrated significant potential for material design and property enhancement to help tackle this problem. Herein, ML techniques were applied to guide the rational design of BC for the targeted acceleration of nonradical pathways. The results showed a high specific surface area, and O% values can significantly enhance nonradical contribution. Furthermore, the two features can be regulated by simultaneously tuning the temperatures and biomass precursors for efficient directed nonradical degradation. Finally, two nonradical-enhanced BCs with different active sites were prepared based on the ML results. This work serves as a proof of concept for applying ML in the synthesis of tailored BC for persulfate activation, thereby revealing the remarkable capability of ML for accelerating bio-based catalyst development.

Rational design of cobalt sulfide anchored on nitrogen-doped carbon derived from cyanobacteria waste enables efficient activation of peroxymonosulfate for organic pollutants oxidation.

With the increasing of eutrophication in water body, algae blooms have become one of the global environmental problems. The cyanobacteria waste has placed a severe burden on the environment and transforming cyanobacteria into functional materials may be a wise approach. Herein, cobaltous sulfide/nitrogen-doped biochar (N-BC/CoSx) composite was synthesized by pyrolysis of cyanobacteria waste. The N-BC/CoSx showed excellent performance in peroxymonosulfate (PMS) activation for enrofloxacin (ENR) degradation, which could remove more than 90% ENR within 60 min. The influencing factors of pH and catalyst dosage on ENR removal efficiency were studied. The N-BC/CoSx showed good recyclability in the cycle runs. The radicals (O2•-, OH andSO4•-) and the non-radical species (charge transfer and 1O2) were generated in the ENR degradation. The cycle of Co(II)/Co(III) m ay contribute to the radical generation process. This work proved that metal sulfide modified cyanobacteria biochar has a specific application value in water pollution control and provides a new method for resource utilization of cyanobacteria.

Analysis of rainwater storage and use recommendations: From the perspective of DBPs generation and their risks.

As a vital freshwater resource, rainwater is usually stored in water cellars in arid regions to solve the daily drinking water problems of the population. However, the status of disinfection by-products (DBPs) generation in cellar water under intermittent disinfection conditions is unclear. Therefore, we investigated the formation and distribution characteristics of DBPs in cellar water under intermittent disinfection conditions for the first time. The results demonstrated that six categories of DBPs were selected for detection after chlorination, including trihalomethanes (THMs), haloacetic acids (HAAs), haloketones (HKs), haloacetonitriles (HANs), halonitromethanes (HNMs), and nitrosamines (NAs), among which HAAs, HKs, and HANs were the major DBPs. Only bromoacetic acid (MBAA), dichloroacetic acid (DCAA), and trichloroacetic acid (TCAA) showed an increasing trend of accumulation as the number of disinfections increased. Meanwhile, the precursor composition was gradually transformed from humic substances to amino acids, and both organic substances were the main precursors of HAAs. The health risk assessment showed that the main carcinogenic and non-carcinogenic risks of cellar water were contributed by NAs and HAAs, respectively, and children are more susceptible to the risks than adults. The best time to drink cellar water is after approximately 12 days of storage, when the total carcinogenic risk is the minimum.

Unexpected chirality transition and inversion mediated by dissolution-aggregation and the odd-even effect.

The evolution of hierarchical chirality at macromolecular and supramolecular levels in biological systems is ubiquitous; however, achieving precise control over transitions between them in polymer systems is still challenging. Here, we reported multiple chiroptical transitions and inversion phenomena in side-chain azobenzene (Azo) polymers, PAzo-l/d-m (m = 3, 6, 7, 8, 9, and 10, where m is the total number of atoms from the chiral stereocenter to the Azo unit), with different distances from the chiral stereocenter to the Azo unit. In the case of m = 3, an unexpected macromolecular-to-supramolecular chirality transition and inversion occurred in situ when the Azo-polymer underwent from a macromolecular-dissolved state to a supramolecular-aggregated state. To our surprise, an exciton-coupling induced multiple chiroptical inversion was observed upon the heating-assisted reassembly treatment, which was demonstrated to be driven by H- to J-aggregation transition. Furthermore, the odd-even effect was first established to regulate the supramolecular helical orientations (left- or right-handedness) in side-chain Azo-polymer assemblies.

NDMA reduction mechanism of UDMH by O3/PMS technology.

Carcinogenic N, N-Dimethylnitrosamine (NDMA) has been reported to generate significantly during ozonation of fuel additive unsymmetrical dimethylhydrazine (UDMH), the combined ozone/Peroxy-Monosulfate (O3/PMS) technology was tried for reducing its formation in this study. The influence of PMS dosages, ozone concentrations, pH, Br- and humic acid (HA) on NDMA formation from UDMH were investigated. In addition, the reduction mechanisms were explored by intermediates identification and Gaussian calculation. The results demonstrated that O3/PMS technology was effective on NDMA reduction, reaching an efficiency of 81% with 80 µM PMS. Higher NDMA reduction rates were achieved by O3/PMS with increasing pH within the scope of research (from 5 to 9), achieving a maximum of 69.9% at pH 9. The presence of bromide ion facilitated NDMA generation during ozonation, but the reduction efficiency by O3/PMS slightly improved from 66.3% to 70.6%. The presence of HA reduced NDMA formation in O3/PMS system. The contribution of SO4•- on NDMA reduction accounted for ~64%, which was higher than that of •OH (41.4%); however, its promotion role on conversing UDMH to NDMA was lower than O3. Therefore, the technology could reduce NDMA formation effectively. In addition, the results of Gaussian calculation manifested that the N atom in -NH2 group of UDMH was easily attacked not only by •OH but also by O3, so it is the key path that determines final NDMA formation. This study would provide reference for reducing NDMA formation during ozonation of UDMH-containing water matrixes.

Correlation Between Prevalence of Selected Enteropathogens and Diarrhea in Children: A Case-Control Study in China.

BACKGROUND: The application of nucleic acid detection methods improves the ability of laboratories to detect diarrheal pathogens, but it also poses new challenges for the interpretation of results. It is often difficult to attribute a diarrhea episode to the detected pathogens. Here we investigated the prevalence of 19 enteropathogens among diarrheal and nondiarrheal children and provided support for understanding the clinical significance of the pathogens. METHODS: A total of 710 fecal samples were collected from children under 5 years old in 2 different regions of China from May 2017 to March 2018, comprising 383 mild to moderate diarrheal cases and 327 nondiarrheal controls. The enteropathogens were detected using real-time polymerase chain reaction (PCR) or real-time reverse transcription PCR (RT-PCR). RESULTS: Enteropathogens were detected in 68.9% of cases and 41.3% of controls. Rotavirus A (adjusted OR [aOR], 9.91; 95% CI, 4.99-19.67), norovirus GI and GII (aOR, 3.82; 95% CI, 2.12-6.89), and Campylobacter jejuni (aOR, 20.12; 95% CI, 2.57-157.38) were significantly associated with diarrhea (P < .05). Adenovirus, norovirus GII, rotavirus A, and enteroaggregative Escherichia coli (pCVD432) gave lower cycle threshold (Ct) values in cases than in controls (P < .05). Rotavirus A and norovirus GII were associated with diarrhea when the Ct values were ≤30 and ≤25, respectively. CONCLUSIONS: The types and loads of enteropathogens are likely to influence the interpretation of the clinical significance of positive results.

Transfer, Amplification, Storage, and Complete Self-Recovery of Supramolecular Chirality in an Achiral Polymer System.

Supramolecular chirality and its complete self-recovery ability are highly mystical in nature and biological systems, which remains a major challenge today. Herein, we demonstrate that partially cross-linked azobenzene (Azo) units can be employed as the potential chiral trigger to fully heal the destroyed helical superstructure in achiral nematic polymer system. Combining the self-assembly of Azo units and terminal hydroxyl groups in polymer side chains allows the vapor-induced chiral nematic phase and covalent fixation of the superstructure via acetal reaction. The induced helical structure of Azo units can be stored by inter-chain cross-linking, even after removal of the chiral source. Most interestingly, the stored chiral information can trigger perfect chiral self-recovery (CSR) behavior after being destroyed by UV light, heat, and solvents. The results pave a new way for producing novel chiroptical materials with reversible chirality from achiral sources.

Comparison of BioFire FilmArray gastrointestinal panel versus Luminex xTAG Gastrointestinal Pathogen Panel (xTAG GPP) for diarrheal pathogen detection in China.

OBJECTIVES: To compare the performance of two syndromic panels: Luminex xTAG Gastrointestinal Pathogen Panel (GPP) and FilmArray Gastrointestinal (GI) panel. METHODS: A total of 243 diarrhea specimens were detected by two panels in parallel, and the inconsistent results were analyzed by real-time PCR or reverse transcription PCR (RT-PCR). The target concentration in specimens was examined by comparing the crossing point values of FilmArray, the median fluorescence intensity of xTAG and the cycle threshold values in any discrepancies. RESULTS: For pathogens detected by both panels, the positive rates of FilmArray GI and xTAG GPP were 65.0% and 48.6%, respectively. The two panels showed high consistency (kappa ≥0.74) in detecting norovirus, rotavirus and Campylobacter, while there was low consistency (kappa ≤0.40) in detecting Cryptosporidium, Salmonella, Shiga toxin-producing Escherichia coli (STEC) and enterotoxigenic Escherichia coli (ETEC). Samples with low concentration targets were more often detected by FilmArray than with xTAG GPP. The xTAG GPP was more likely to be affected by amplification inhibitors. Several defects of xTAG GPP were found in detecting ETEC. CONCLUSIONS: FilmArray was more sensitive. For specimens with low target concentrations or containing ETEC heat stable enterotoxin, the false negatives of xTAG GPP need to be considered.

Evaluation of the BioFire FilmArray Gastrointestinal Panel and Real-Time Polymerase Chain Reaction Assays for the Detection of Major Diarrheagenic Pathogens by a Multicenter Diarrheal Disease Surveillance Program in China.

In the field of the detection of pathogens responsible for infectious diarrhea, multiplex nucleic acids detection technology has attracted attention due to its ability to simultaneously screen a wide range of pathogens, its simplicity to operate and a faster turnaround time. We conducted a three-center evaluation that compared the BioFire FilmArray gastrointestinal panel (FA GI) and real-time polymerase chain reaction (PCR) assays for the detection of pathogens from 462 clinical diarrhea specimens, and characterized the distribution of various pathogens that were analyzed. The sensitivity of FA GI was 100% for 13 pathogens and 93.8-98.3% for 4 pathogens, but low for Salmonella (60.5%) and adenovirus (88.9%). The sensitivity per pathogen of real-time PCR assays was lower than that observed with FA GI. The specificity of FA GI and real-time PCR assays per pathogen was greater than 94.5% and 99%, respectively. FA GI and real-time PCR assays detected ≥1 pathogen in 339 (73.4%) and 297 (64.3%) samples, respectively, and 324 (70.1%) samples were considered as positive according to the reference standard. Multiple pathogens were detected in 37.2% and 24.9% of samples by FA GI and real-time PCR assays, respectively. Norovirus GI/GII and Campylobacter were less associated with coinfections. The positive rates of some pathogens varied among the three regions of China. Molecular methods can help squickly identify the cause of diarrhea and provide valuable information for early diagnosis and optimal patient therapy.

A case report on mother-to-child transmission of Brucella in human, China.

BACKGROUND: Human brucellosis is endemic in China and commonly occurs through contact with infected animals from working with livestock or consumption of unpasteurized dairy products. Although rare, human-to-human, and possible sexual transmission, of Brucella has been reported. In this report, we describe a case of likely mother-to-child transmission of Brucella in Hunan Province, China. CASE PRESENTATION: Between June and October 2016, a 28-year old man sought care for testicular swelling and pain at several health facilities. His 26-year old wife developed intermittent fever along with right thigh and hip pain between November 2016 and February 2017 respectively. On April 5, 2017, the female patient delivered a male neonate at 34 weeks of gestation through natural labor. The child's venal blood sample was cultured on April 5, 2017. Brucella was isolated and identified on April 12, 2017. On the same date, serum antibodies of the father and mother were above 1:100 (based on the serum agglutination test [SAT]). The strains isolated from the mother and neonate were identified as Brucella melitensis biotype 1. CONCLUSIONS: This report highlights a family cluster of brucellosis. Culture results strongly support mother-to-child transmission, and a high probability of sexual transmission from husband to wife.