Towards Sustainable Production of Polybutylene Adipate Terephthalate: Non-biological Catalytic Syntheses of Biomass-derived Constituents.

Renewable chemicals, which are made from renewable resources such as biomass, have attracted significant interest as substitutes for natural gas- or petroleum-derived chemicals to enhance the sustainability of the chemical and petrochemical industries. Polybutylene adipate terephthalate (PBAT), which is a copolyester of 1,4-butanediol (1,4-BDO), adipic acid (AA), and dimethyl terephthalate (DMT) or terephthalic acid (TPA), has garnered significant interest as a biodegradable polymer. This study assesses the non-biological production of PBAT monomers from biomass feedstocks via heterogeneous catalytic reactions. The biomass-based catalytic routes to each monomer are analyzed and compared to conventional routes. Although no fully commercialized catalytic processes for direct conversion of biomass into 1,4-BDO, AA, DMT, and TPA are available, emerging and promising catalytic routes have been proposed. The proposed biomass-based catalytic pathways toward 1,4-BDO, AA, DMT, and TPA are not yet fully competitive with conventional fossil fuel-based pathways mainly due to high feedstock prices and the existence of other alternatives. However, given continuous technological advances in the renewable production of PBAT monomers, bio-based PBAT should be economically viable in the near future.

Response of particle-attached and free-living bacterial communities to Microcystis blooms.

The massive proliferation of Microcystis threatens freshwater ecosystems and degrades water quality globally. Understanding the mechanisms that contribute to Microcystis growth is crucial for managing Microcystis blooms. The lifestyles of bacteria can be classified generally into two groups: particle-attached (PA; > 3 µm) and free-living (FL; 0.2-3.0 µm). However, little is known about the response of PA and FL bacteria to Microcystis blooms. Using 16S rRNA gene high-throughput sequencing, we investigated the stability, assembly process, and co-occurrence patterns of PA and FL bacterial communities during distinct bloom stages. PA bacteria were phylogenetically different from their FL counterparts. Microcystis blooms substantially influenced bacterial communities. The time decay relationship model revealed that Microcystis blooms might increase the stability of both PA and FL bacterial communities. A contrasting community assembly mechanism was observed between the PA and FL bacterial communities. Throughout Microcystis blooms, homogeneous selection was the major assembly process that impacted the PA bacterial community, whereas drift explained much of the turnover of the FL bacterial community. Both PA and FL bacterial communities could be separated into modules related to different phases of Microcystis blooms. Microcystis blooms altered the assembly process of PA and FL bacterial communities. PA bacterial community appeared to be more responsive to Microcystis blooms than FL bacteria. Decomposition of Microcystis blooms may enhance cooperation among bacteria. Our findings highlight the importance of studying bacterial lifestyles to understand their functions in regulating Microcystis blooms. KEY POINTS: • Microcystis blooms alter the assembly process of PA and FL bacterial communities • Microcystis blooms increase the stability of both PA and FL bacterial communities • PA bacteria seem to be more responsive to Microcystis blooms than FL bacteria.

Dynamic response of bacterial communities to Microcystis blooms: A three-year study.

Although nutrient availability is widely recognized as the driving force behind Microcystis blooms, identifying the microorganisms that play a pivotal role in their formation is a challenging task. Our understanding of the contribution of bacterial communities to the development of Microcystis blooms remains incomplete, despite the fact that the relationship between Microcystis and bacterial communities has been extensively investigated. Most studies have focused on their interaction for a single year rather than for multiple years. To determine key bacteria crucial for the formation of Microcystis blooms, we collected samples from three sites in the Daechung Reservoir (Chuso, Hoenam, and Janggye) over three years (2017, 2019, and 2020). Our results indicated that Microcystis bloom-associated bacterial communities were more conserved across stations than across years. Bacterial communities could be separated into modules corresponding to the different phases of Microcystis blooms. Dolichospermum and Aphanizomenon belonged to the same module, whereas the module of Microcystis was distinct. The microbial recurrent association network (MRAN) showed that amplicon sequence variants (ASVs) directly linked to Microcystis belonged to Pseudanabaena, Microscillaceae, Sutterellaceae, Flavobacterium, Candidatus Aquiluna, Bryobacter, and DSSD61. These ASVs were also identified as key indicators of the bloom stage, indicating that they were fundamental biological elements in the development of Microcystis blooms. Overall, our study highlights that, although bacterial communities change annually, they continue to share core ASVs that may be crucial for the formation and maintenance of Microcystis blooms.

High-resolution processing and sigmoid fusion modules for efficient detection of small objects in an embedded system.

Recent advances in deep learning realized accurate, robust detection of various types of objects including pedestrians on the road, defect regions in the manufacturing process, human organs in medical images, and dangerous materials passing through the airport checkpoint. Specifically, small object detection implemented as an embedded system is gaining increasing attention for autonomous vehicles, drone reconnaissance, and microscopic imagery. In this paper, we present a light-weight small object detection model using two plug-in modules: (1) high-resolution processing module (HRPM ) and (2) sigmoid fusion module (SFM). The HRPM efficiently learns multi-scale features of small objects using a significantly reduced computational cost, and the SFM alleviates mis-classification errors due to spatial noise by adjusting weights on the lost small object information. Combination of HRPM and SFM significantly improved the detection accuracy with a low amount of computation. Compared with the original YOLOX-s model, the proposed model takes a two-times higher-resolution input image for higher mean average precision (mAP) using 57% model parameters and 71% computation in Gflops. The proposed model was tested using real drone reconnaissance images, and provided significant improvement in detecting small vehicles.

The cyanobactericidal bacterium Paucibacter aquatile DH15 caused the decline of Microcystis and aquatic microbial community succession: A mesocosm study.

Microcystis blooms pose a major threat to the quality of drinking water. Cyanobactericidal bacteria have attracted much attention in the research community as a vehicle for controlling Microcystis blooms because of their ecological safety. Nonetheless, most studies on cyanobactericidal bacteria have been conducted on a laboratory scale but have not been scaled-up as field experiments. Thus, our understanding of the microbial response to cyanobactericidal bacteria in natural ecosystems remains elusive. Herein, we applied Paucibacter aquatile DH15 to control Microcystis blooms in a 1000 L mesocosm experiment and demonstrated its potential with the following results: (1) DH15 reduced Microcystis cell density by 90.7% within two days; (2) microcystins released by Microcystis death decreased to the control level in four days; (3) during the cyanobactericidal processes, the physicochemical parameters of water quality remained safe for other aquatic organisms; and (4) the cyanobactericidal processes promoted the growth of eukaryotic microalgae, replacing cyanobacteria. The cyanobactericidal processes accelerated turnover rates, decreased stability, and altered the functional profile of the microbial community. Network analysis demonstrated that this process resulted in more complex interactions between microbes. Overall, our findings suggest that strain DH15 could be considered a promising candidate for controlling Microcystis blooms in an eco-friendly manner.

Percutaneous stone removal using a compliant balloon after papillary balloon dilatation.

PURPOSE: To evaluate the safety and efficacy of percutaneous stone removal using a compliant balloon after papillary balloon dilatation. MATERIAL AND METHODS: Between March 2014 and May 2020, 123 patients with choledocholithiasis, in whom endoscopy was unsuccessful, were enrolled in this study. The ampulla of Vater was dilated using a noncompliant balloon, and stone removal was attempted via a pushing maneuver using an endoscopic stone extraction balloon. Clinical and technical success rates, complications, and risk factors for failure and complications were evaluated. RESULTS: Biliary stones were completely removed in 118 of 123 patients. Major complications occurred in five patients. One patient experienced duodenal bleeding, which was successfully treated by endoscopy. Hemobilia occurred in three patients, which required transfusion, and one patient experienced four days of abdominal pain. Minor complications, including self-limiting pain, effusion, minimal hemobilia, elevated amylase and fever, occurred in 21 patients. Stone size was the only significant risk factor associated with the rate of complications (Odds ratio: 1.14, 95% confidence interval = 1.04, 1.26). Bilirubin and white blood cell levels significantly decreased after the procedure. CONCLUSION: Percutaneous stone removal using a compliant balloon after papillary balloon dilatation is a safe and effective method in patients in whom endoscopic or surgical treatment is not feasible. Abbreviations: ERCP: endoscopic retrograde cholangiopancreatography; PTBD: percutaneous transhepatic biliary drainage.

Aquariibacter albus gen. nov., sp. nov., a new member of the order Burkholderiales, isolated from a freshwater aquarium.

A novel bacterium, strain SJAQ100T, was isolated from a freshwater aquarium and was characterized taxonomically and phylogenetically. Strain SJAQ100T was a Gram-stain-negative, aerobic, rod-shaped and non-motile bacterium. The strain grew optimally with 0 % NaCl and at 25-37 °C on Reasoner's 2A agar. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that the strain SJAQ100T clustered with members of Burkholderiales incertae sedis in the order Burkholderiales, but sequence similarities to known species were less than 96.5 %. The genomic DNA G+C content of strain SJAQ100T was 71.2 mol%. Genomic comparisons of strain SJAQ100T with species in the order Burkholderiales were made using the Genome-to-Genome Distance Calculator, average nucleotide identity and average amino acid identity analyses (values indicated ≤22.1, ≤78.1, and ≤68.1 % respectively). Strain SJAQ100T contained C16 : 0 and C16 : 1 ω7c/C16 : 1 ω6c as major fatty acids and Q-8 as the major quinone. The major polyamines were putrescine and cadaverine. Strain SJAQ100T contained phosphatidylethanolamine and diphosphatidylglycerol as major polar lipids. Based on the genotypic, chemotaxonomic and phenotypic results, strain SJAQ100T represents a novel genus and species, Aquariibacter albus gen. nov., sp. nov., which belongs to order Burkholderiales and the class Betaproteobacteria. The type strain is SJAQ100T (=KCTC 72203T=CGMCC 1.18869T=MCC 4385T).

COVID-19 mask waste to energy via thermochemical pathway: Effect of Co-Feeding food waste.

In this study, co-pyrolysis of single-use face mask (for the protection against COVID-19) and food waste was investigated for the purpose of energy and resource valorization of the waste materials. To this end, disposable face mask (a piece of personal protective equipment) was pyrolyzed to produce fuel-range chemicals. The pyrolytic gas evolved from the pyrolysis of the single-use face mask consisted primarily of non-condensable permanent hydrocarbons such as CH4, C2H4, C2H6, C3H6, and C3H8. An increase in pyrolysis temperature enhanced the non-condensable hydrocarbon yields. The pyrolytic gas had a HHV of >40 MJ kg-1. In addition, hydrocarbons with wider carbon number ranges (e.g., gasoline-, jet fuel-, diesel-, and motor oil-range hydrocarbons) were produced in the pyrolysis of the disposable face mask. The yields of the gasoline-, jet fuel-, and diesel-range hydrocarbons obtained from the single-use mask were highest at 973 K. The pyrolysis of the single-use face mask yielded 14.7 wt% gasoline-, 18.4 wt% jet fuel-, 34.1 wt% diesel-, and 18.1 wt% motor oil-range hydrocarbons. No solid char was produced via the pyrolysis of the disposable face mask. The addition of food waste to the pyrolysis feedstock led to the formation of char, but the presence of the single-use face mask did not affect the properties and energy content of the char. More H2 and less hydrocarbons were produced by co-feeding food waste in the pyrolysis of the disposable face mask. The results of this study can contribute to thermochemical management and utilization of everyday waste as a source of energy.

Co-pyrolysis of food waste and wood bark to produce hydrogen with minimizing pollutant emissions.

In this study, the co-pyrolysis of food waste with lignocellulosic biomass (wood bark) in a continuous-flow pyrolysis reactor was considered as an effective strategy for the clean disposal and value-added utilization of the biowaste. To achieve this aim, the effects of major co-pyrolysis parameters such as pyrolysis temperature, the flow rate of the pyrolysis medium (nitrogen (N2) gas), and the blending ratio of food waste/wood bark on the yields, compositions, and properties of three-phase pyrolytic products (i.e., non-condensable gases, condensable compounds, and char) were investigated. The temperature and the food waste/wood bark ratio were found to affect the pyrolytic product yields, while the N2 flow rate did not. More non-condensable gases and less char were produced at higher temperatures. For example, as the temperature was increased from 300 °C to 700 °C, the yield of non-condensable gases increased from 6.3 to 17.5 wt%, while the yield of char decreased from 63.6 to 30.6 wt% for the co-pyrolysis of food waste and wood bark at a weight ratio of 1:1. Both the highest yield of hydrogen (H2) gas and the most significant suppression of the formation of phenolic and polycyclic aromatic hydrocarbon (PAH) compounds were achieved with a combination of food waste and wood bark at a weight ratio of 1:1 at 700 °C. The results suggest that the synergetic effect of food waste and lignocellulosic biomass during co-pyrolysis can be exploited to increase the H2 yield while limiting the formation of phenolic compounds and PAH derivatives. This study has also proven the effectiveness of co-pyrolysis as a process for the valorization of biowaste that is produced by agriculture, forestry, and the food industry, while reducing the formation of harmful chemicals.

Tabrizicola algicola sp. nov. isolated from culture of microalga Ettlia sp.

A novel Gram-stain-negative, aerobic, non-spore-forming, non-motile, and rod-shaped bacterium, strain ETT8T was isolated from a chemostat culture of microalga Ettlia sp. YC001. Optimal growth was with 0-2% NaCl and at 25-37 °C on R2A medium. Phylogenetic analysis based on the 16S rRNA gene and genome sequence showed that strain ETT8T belongs to the genus Tabrizicola, with the close neighbours being T. sediminis DRYC-M-16T (98.1 %), T. alkalilacus DJCT (97.6 %), T. fusiformis SY72T (96.9 %), T. piscis K13M18T (96.8 %), and T. aquatica RCRI19T (96.5 %). The genomic comparison of strain ETT8T with type species in the genus Tabrizicola was analysed using the genome-to-genome distance calculator (GGDC), average nucleotide identity (ANI), and average amino acid identity (AAI) (values indicated ≤17.7, ≤75.4 and ≤71.9 %, respectively). The genomic DNA G+C content of strain ETT8T was 64.4 %, plus C18 : 1 ω6c and C18 : 0-iso were the major fatty acids and Q-10 the major respiratory quinone. Strain ETT8T contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine aminolipid, and four unidentified lipids as the major polar lipids. Based on the chemotaxonomic, genotypic, and phenotype results, strain ETT8T was recognized as a novel species of the genus Tabrizicola for which the name Tabrizicola algicola sp. nov. is proposed. The type strain is ETT8T (=KCTC 72206T=JCM 31893T=MCC 4339T).

Reduction of polycyclic compounds and biphenyls generated by pyrolysis of industrial plastic waste by using supported metal catalysts: A case study of polyethylene terephthalate treatment.

The accumulation of industrial plastic waste in the environment is a global growing concern. Thermochemical process is a preferred method to dispose plastic waste mainly because it can reduce volume of the waste; however, the thermochemical disposal of plastic waste can emit harmful chemical species such as benzene derivatives and polycyclic hydrocarbons. As an effort to overcome this challenge, supported metal catalysts (carbon-supported Pd and Pt catalysts) were used to inhibit the formation of polycyclic compounds and biphenyl derivatives by pyrolysis of polyethylene terephthalate (PET). Less polycyclic compounds and biphenyl derivatives were generated during the Pd or Pt-catalyzed PET pyrolysis than non-catalytic PET pyrolysis. The concentrations of polycyclic compounds and biphenyl derivatives were 107 % and 56 % lower for the Pt-catalyzed pyrolysis at 700 °C than non-catalytic pyrolysis, respectively. The Pt catalyst was more effective to suppress the generation of polycyclic compounds and biphenyl derivatives during the PET pyrolysis than the Pd catalyst at temperatures from 400 to 800 °C. This was likely because the Pt sites catalyzes decyclization reaction and/or free radical mechanism that is dominant in thermal cracking of carbonaceous substances such as PET. The results of this study would help develop environmentally friendly industrial plastic waste treatment methods via thermochemical processes.

Factors affecting tumor recurrence after curative surgery for NSCLC: impacts of lymphovascular invasion on early tumor recurrence.

BACKGROUND: Although surgery is potentially curative treatment for non-small cell lung cancer (NSCLC), the risk of postoperative disease recurrence is still high. This study was conducted to assess the factors associated with postoperative tumor recurrence in patients who underwent curative surgery for NSCLC. METHODS: One hundred seventy-one patients who underwent curative surgery for NSCLC were included in this study. Clinicopathological factors of histologic type, pathologic TNM stage, T stage, N stage, lymphovascular invasion (LVI), perineural invasion (PNI), surgical procedure, adjuvant chemotherapy and adjuvant radiotherapy were investigated. Gender, age, and clinicopathologic factors were included in univariate and multivariate analyses using the Kaplan-Meier method and Cox proportional hazards model, respectively. Mann-Whitney U and Kruskal-Wallis tests were used to investigate the significance of differences in recurrence-free interval (RFI) according to clinicopathological factors. RESULTS: Median RFI was 20 months. Univariate and multivariate analyses for overall recurrence identified T stage, N stage, and LVI as significant factors (P=0.045, 0.044, and <0.001, respectively). Pathologic stage (P=0.005) was the only factor that was significantly associated with locoregional recurrence. T stage (P=0.040) and LVI (P<0.001) were significantly associated with distant recurrence. The difference in 2-year freedom from recurrence between LVI positive and negative groups was significant (14.9% vs. 44.6%, P<0.001). LVI was the only factor that was significantly associated with a shortened mean RFI (P<0.001). CONCLUSIONS: LVI had a significant effect on both overall and distant recurrence rates as well as on early tumor recurrence after curative surgery for NSCLC.

A comparison of the performance of anatomical MRI and DTI in diagnosing carpal tunnel syndrome.

PURPOSE: To compare the performance of anatomical magnetic resonance imaging (MRI) with that of diffusion tensor imaging (DTI) in the diagnosis of carpal tunnel syndrome (CTS). MATERIALS AND METHODS: We performed 3T anatomical MRI and DTI on 42 patients and 42 age-matched controls. The median nerve cross-sectional area (CSA), relative median nerve signal intensity, and palmar bowing of the flexor retinaculum, assessed with anatomical MRI, and fractional anisotropy (FA) and apparent diffusion coefficient of the median nerve, assessed with DTI, were measured at four locations: the hamate level, the pisiform level (P0), the level located 1cm proximal to the P0 level (P1), and the distal radioulnar joint level (DR). Adding the ratios and differences of the median nerve parameters between the measurements at the DR and other locations to the diagnostic parameters, we evaluated the area under the receiver operating characteristic curves (AUCs) of all the diagnostic parameters of both scans. RESULTS: The AUCs of FA(P1) (0.814) and FA(P0) (0.824) in DTI were larger than the largest AUC for anatomical MRI, CSA(P1) (0.759). However, the receiver operating characteristics of the three parameters were not significantly different (P>0.1). The sensitivity and specificity of CSA(P1) (76.2% and 73.8%) and FA(P1) (73.8% and 76.2%) increased after inclusive and exclusive combination to 90.5% each. CONCLUSION: The individual performances of both scans were not significantly different in diagnosing CTS. Measuring both CSA and FA at P1 may be useful and efficient to utilize the merits of both scans and to increase the CTS diagnostic performance.