Laparoscopic Extraperitoneal Approach for Lateral Pelvic Node Dissection in Rectal Cancer: Techniques and Short-Term Outcomes.

BACKGROUND: Lateral pelvic lymph node dissection has been performed selectively in rectal cancer cases; however, it involves highly skilled techniques because of the complex adjacent anatomical structures. MATERIALS AND METHODS: Laparoscopic EP-LPND was performed in Korea University Anam Hospital from June 2018, and short-term surgical outcomes were analyzed from June to December 2018. Among the patients with histologically diagnosed rectal adenocarcinoma, patients who were suspected Lateral pelvic lymph node metastasis at magnetic resonance imaging were selected for this procedure. RESULTS: Seven patients underwent laparoscopic extraperitoneal approach for lateral pelvic lymph node dissection in the study period. The mean number of retrieved lymph node was 4.57, and metastatic lymph nodes were identified in 3 patients (42.8%). All of the lymph nodes with suspected metastasis preoperatively were removed in postoperative images. There was no immediate postoperative complication beyond the moderate grade associated with lateral pelvic lymph node dissection. The median follow-up was 9 months, and there were no local recurrence nor complications related to sexual and voiding functions. CONCLUSIONS: The laparoscopic extraperitoneal approach might be an efficient way to perform lateral pelvic lymph node dissection using the same principles as the conventional method without violation of the peritoneum.

Midline incision vs. transverse incision for specimen extraction is not a significant risk factor for developing incisional hernia after minimally invasive colorectal surgery: multivariable analysis of a large cohort from a single tertiary center in Korea.

BACKGROUND: Incisional hernia (IH) is a commonly encountered problem even in the era of minimally invasive surgery (MIS). Numerous studies on IH are available in English literature, but there are lack of data from the Eastern part of the world. This study aimed to evaluate the risk factors as well as incidence of IH by analyzing a large cohort collected from a single tertiary center in Korea. METHODS: Among a total number of 4276 colorectal cancer patients who underwent a surgical resection from 2006 to 2019 in Korea University Anam Hospital, 2704 patients (2200 laparoscopic and 504 robotic) who met the inclusion criteria were analyzed. IH was confirmed by each patient's diagnosis code registered in the hospital databank based on physical examination and/or computed tomography findings. Clinical data including specimen extraction incision (transverse or vertical midline) were compared between IH group and no IH group. Risk factors of developing IH were assessed by utilizing univariable and multivariable analyses. RESULTS: During the median follow-up of 41 months, 73 patients (2.7%) developed IH. Midline incision group (n = 1472) had a higher incidence of IH than that of transverse incision group (n = 1232) (3.5% vs. 1.7%, p = 0.003). The univariable analysis revealed that the risk factors of developing IH were old age, female gender, obesity, co-morbid cardiovascular disease, transverse incision for specimen extraction, and perioperative bleeding requiring transfusion. However, on multivariable analysis, specimen extraction site was not significant in developing IH and transfusion requirement was the strongest risk factor. CONCLUSIONS: IH development after MIS is uncommon in Korean patients. Multivariable analysis suggests that specimen extraction site can be flexibly chosen between midline and transverse incisions, with little concern about risk of developing IH. Careful efforts are required to minimize operative bleeding because blood transfusion is a strong risk factor for developing IH.

Plastic-inhabiting fungi in marine environments and PCL degradation activity.

Plastic waste has a negative impact on marine ecosystems and the quantity of this source of anthropogenic pollution continues to increase. Several studies have investigated plastic biodegradation using various microorganisms. In this study, we isolated fungi from polyethylene terephthalate (PET) waste on Korean seacoasts and evaluated their ability to degrade plastic by comparing the diameters of the clear zones they formed on polycaprolactone (PCL) agar. We isolated 262 strains from 47 plastic waste sources and identified 108 fungal species via molecular methods. The PCL agar assay revealed that 87 species presented with varying degrees of PCL degradation capacity. Among them, certain fungal species were strong PCL degraders. The present study demonstrated the possibility that some fungi inhabiting plastic could potentially degrade it in the marine environment. We believe that the discoveries made herein lay theoretical and practical foundations for the development of novel bioremediation systems for marine plastispheres and help mitigate the environmental pollution issues related to plastic wastes.

Dynamic molecular conformational change leading to energy transfer in F8-5% BSP copolymer revealed by single-molecule spectroscopy.

Polyfluorene-based copolymers such as poly(9,9-dioctylfluorene)-alt-5% [bis-N,N'-(4-butylphenyl)-bis-N,N'-phenyl-1,4-phenylenediamine] (F8-5% BSP) are efficient blue-emitting polymers with various electronic phases: F8 blue-emitting glassy phase, F8 ordered more red-emitting ß-phase, and F8/BSP charge transfer (CT) state. Polymer light-emitting device performance and color purity can be significantly improved by forming ß-phase segments. However, the role of the ß-phase on energy transfer (ET) among glassy F8, ß-phase, and F8/BSP CT state is unclear. Herein, we identify dynamic molecular conformation-controlled ET from locally excited states to either the CT state or ß-phase in light-emitting copolymers. By conducting single-molecule spectroscopy for single F8-5% BSP chains, we find inefficient intra-chain ET from glassy segments to the CT state, while efficient ET from the glassy to the ß-phase. Spontaneous and reversible CT on-off emission is observed both in the presence and absence of the ß-phase. The density functional theory calculations reveal the origin of the on-chain CT state and indicate this CT emission on-off switching behavior could be related to molecule torsional motion between BSP and F8 units. The population of the CT state by ET can be increased via through-space interaction between the F8 block and the BSP unit on a self-folded chain. Temperature-dependent single-molecule spectroscopy confirms such interaction showing a gradual increase in intensity of the CT emission with the temperature. Based on these observations, we propose the dynamic molecular motion-induced conformation change as the origin of the glassy-to-CT ET, and thermal energy may provide the activation for such a change to enhance the ET from glassy or ß-phases to the CT state.

Reactivity Differences Enable ROS for Selective Ablation of Bacteria.

An effective strategy to engineer selective photodynamic agents to surmount bacterial-infected diseases, especially Gram-positive bacteria remains a great challenge. Herein, we developed two examples of compounds for a proof-of-concept study where reactive differences in reactive oxygen species (ROS) can induce selective ablation of Gram-positive bacteria. Sulfur-replaced phenoxazinium (NBS-N) mainly generates a superoxide anion radical capable of selectively killing Gram-positive bacteria, while selenium-substituted phenoxazinium (NBSe-N) has a higher generation of singlet oxygen that can kill both Gram-positive and Gram-negative bacteria. This difference was further evidenced by bacterial fluorescence imaging and morphological changes. Moreover, NBS-N can also successfully heal the Gram-positive bacteria-infected wounds in mice. We believe that such reactive differences may pave a general way to design selective photodynamic agents for ablating Gram-positive bacteria-infected diseases.

Work Restrictions for Healthcare Personnel with Potential In-hospital Exposure to SARS-CoV-2: Experience at a Tertiary Hospital.

Applying work restrictions for asymptomatic healthcare personnel (HCP) with potential exposure to coronavirus disease 2019 (COVID-19) is recommended to prevent transmission from potentially contagious HCP to patients and other HCP. However, it can lead to understaffing, which threatens the safety of both patients and HCP. We evaluated 203 COVID-19 exposure events at a single tertiary hospital from January 2020 to June 2021. A total of 2,365 HCP were potentially exposed, and work restrictions were imposed on 320 HCP, leading to the loss of 3,311 working days. However, only one of the work-restricted HCP was confirmed with COVID-19. During the study period, the work restriction measures might be taken excessively compared to their benefit, so establishing more effective standards for work restriction is required.

Ultrasensitive Strain Sensor Based on Pre-Generated Crack Networks Using Ag Nanoparticles/Single-Walled Carbon Nanotube (SWCNT) Hybrid Fillers and a Polyester Woven Elastic Band.

Flexible strain sensors are receiving a great deal of interest owing to their prospective applications in monitoring various human activities. Among various efforts to enhance the sensitivity of strain sensors, pre-crack generation has been well explored for elastic polymers but rarely on textile substrates. Herein, a highly sensitive textile-based strain sensor was fabricated via a dip-coat-stretch approach: a polyester woven elastic band was dipped into ink containing single-walled carbon nanotubes coated with silver paste and pre-stretched to generate prebuilt cracks on the surface. Our sensor demonstrated outstanding sensitivity (a gauge factor of up to 3550 within a strain range of 1.5-5%), high stability and durability, and low hysteresis. The high performance of this sensor is attributable to the excellent elasticity and woven structure of the fabric substrate, effectively generating and propagating the prebuilt cracks. The strain sensor integrated into firefighting gloves detected detailed finger angles and cyclic finger motions, demonstrating its capability for subtle human motion monitoring. It is also noteworthy that this novel strategy is a very quick, straightforward, and scalable method of fabricating strain sensors, which is extremely beneficial for practical applications.

One-Step Sixfold Cyanation of Benzothiadiazole Acceptor Units for Air-Stable High-Performance n-Type Organic Field-Effect Transistors.

Reported here is a new high electron affinity acceptor end group for organic semiconductors, 2,1,3-benzothiadiazole-4,5,6-tricarbonitrile (TCNBT). An n-type organic semiconductor with an indacenodithiophene (IDT) core and TCNBT end groups was synthesized by a sixfold nucleophilic substitution with cyanide on a fluorinated precursor, itself prepared by a direct arylation approach. This one-step chemical modification significantly impacted the molecular properties: the fluorinated precursor, TFBT IDT, a poor ambipolar semiconductor, was converted into TCNBT IDT, a good n-type semiconductor. The electron-deficient end group TCNBT dramatically decreased the energy of the highest occupied and lowest unoccupied molecular orbitals (HOMO/LUMO) compared to the fluorinated analogue and improved the molecular orientation when utilized in n-type organic field-effect transistors (OFETs). Solution-processed OFETs based on TCNBT IDT exhibited a charge-carrier mobility of up to µe ≈0.15 cm2 V-1 s-1 with excellent ambient stability for 100 hours, highlighting the benefits of the cyanated end group and the synthetic approach.

Prospective study of oncologic outcomes after laparoscopic modified complete mesocolic excision for non-metastatic right colon cancer (PIONEER study): study protocol of a multicentre single-arm trial.

BACKGROUND: The introduction of complete mesocolic excision (CME) with central vascular ligation (CVL) for right-sided colon cancer has improved the oncologic outcomes. Recently, we have introduced a modified CME (mCME) procedure that keeps the same principles as the originally described CME but with a more tailored approach. Some retrospective studies have reported the favourable oncologic outcomes of laparoscopic mCME for right-sided colon cancer; however, no prospective multicentre study has yet been conducted. METHODS: This study is a multi-institutional, prospective, single-arm study evaluating the oncologic outcomes of laparoscopic mCME for adenocarcinoma arising from the right side of the colon. A total of 250 patients will be recruited from five tertiary referral centres in South Korea. The primary outcome of this study is 3-year disease-free survival. Secondary outcome measures include 3-year overall survival, incidence of surgical complications, completeness of mCME, and distribution of metastatic lymph nodes. The quality of laparoscopic mCME will be assessed on the basis of photographs of the surgical specimen and the operation field after the completion of lymph node dissection. DISCUSSION: This is a prospective multicentre study to evaluate the oncologic outcomes of laparoscopic mCME for right-sided colon cancer. To the best of our knowledge, this will be the first study to prospectively and objectively assess the quality of laparoscopic mCME. The results will provide more evidence about oncologic outcomes with respect to the quality of laparoscopic mCME in right-sided colon cancer. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT03992599 (June 20, 2019). The posted information will be updated as needed to reflect protocol amendments and study progress.

A highly sensitive molecular structural probe applied to in situ biosensing of metabolites using PEDOT:PSS.

A large amount of research within organic biosensors is dominated by organic electrochemical transistors (OECTs) that use conducting polymers such as poly(3,4-ethylene dioxythiophene) doped with poly(styrenesulfonate) (PEDOT:PSS). Despite the recent advances in OECT-based biosensors, the sensing is solely reliant on the amperometric detection of the bioanalytes. This is typically accompanied by large undesirable parasitic electrical signals from the electroactive components in the electrolyte. Herein, we present the use of in situ resonance Raman spectroscopy to probe subtle molecular structural changes of PEDOT:PSS associated with its doping level. We demonstrate how such doping level changes of PEDOT:PSS can be used, for the first time, on operational OECTs for sensitive and selective metabolite sensing while simultaneously performing amperometric detection of the analyte. We test the sensitivity by molecularly sensing a lowest glucose concentration of 0.02 mM in phosphate-buffered saline solution. By changing the electrolyte to cell culture media, the selectivity of in situ resonance Raman spectroscopy is emphasized as it remains unaffected by other electroactive components in the electrolyte. The application of this molecular structural probe highlights the importance of developing biosensing probes that benefit from high sensitivity of the material's structural and electrical properties while being complimentary with the electronic methods of detection.

Co3O4/Au Hybrid Nanostructures as Efficient Peroxidase Mimics for Colorimetric Biosensing.

Nanomaterials with enzyme-like characteristics (nanozymes) have emerged as potential replacements for natural enzymes due to their potential to overcome several critical limitations of natural enzymes, including low stability as well as high costs in preparation and purification. Herein, we have developed hybrid nanostructures that incorporate cobalt oxide nanoparticles (Co3O4 NPs) and gold nanoclusters (AuNCs) through electrostatic attraction induced by simple incubation in an aqueous buffer for 2 hours. Owing to the synergistic effect of Co3O4 NPs and AuNCs, the constructed Co3O4/Au hybrid nanostructures yielded highly enhanced peroxidase-like activity and enabled rapid catalytic oxidation of a chromogenic substrate, 3,3',5,5'-tetramethylbenzidine (TMB), producing a blue colored solution depending on the amount of H2O2. Moreover, we observed catalytic activity of the Co3O4/Au hybrid over a broad pH range, especially at physiologically relevant pH in the range of 5.0-7.4, which is advantageous for applications in biological systems. Using the hybrid as peroxidase mimic, we successfully determined the level of target H2O2 or glucose by coupling with glucose oxidase with excellent specificity and sensitivity. Based on this study, we expect that Co3O4/Au hybrid nanostructures can serve as potent peroxidase mimics for the detection of clinically important target molecules.

Lactobacilus nuruki sp. nov., isolated from Nuruk, a Korean fermentation starter.

A rod-shaped, Gram-stain-positive, non-flagellated, facultatively anaerobic bacterium, designated SYF10-1aT, was isolated from Nuruk, a Korean traditional fermentation starter. It grew at 4-40 °C (optimum 37 °C), at pH 3.0-9.0 (optimum, pH 7.0) and with 0-5 % (w/v) NaCl. Phylogenetic analysis using 16S rRNA gene sequences revealed that strain SYF10-1aT belonged to the genus Lactobacillus and showed the highest sequence similarity of 98.7 % to Lactobacillus crustorum LMG 23699T. A comparison of two housekeeping genes, pheS and rpoA, supported the suggestion that strain SYF10-1aT fell within the radius of the genus Lactobacillus, but was clearly separated from its closest related species. The average nucleotide identity value and digital DNA-DNA hybridization value between strain SYF10-1aT and the most closely related species,L. crustorum LMG 23699T, were 80.5 and 33.3 %, respectively. The predominant cellular fatty acids were C16 : 0, C18 : 1ω9c, C18 : 1ω7c and summed feature 3 (including iso-C15 : 0 2-OH and/or C16 : 1ω7c). Polar lipids were diphosphatidylglycerol, phosphatidylglycerol, two unidentified aminolipids and two unidentified glycolipids. The cell-wall peptidoglycan was of the A4α type with an interpeptide bridge comprising l-Lys-d-Asp. The DNA G+C content was 34.2 mol%. On the basis of this taxonomic study, strain SYF10-1aT represents a novel species within the genus Lactobacillus, for which the name Lactobacillus nuruki sp. nov. is proposed. The type strain is SYF10-1aT (=KACC 18726T=NBRC 112011T).

The Prevalence of Cerebral Microbleeds in Non-Demented Parkinson's Disease Patients.

BACKGROUND: Cerebral microbleeds (CMBs) are associated with cerebrovascular risk factors and cognitive dysfunction among patients with Parkinson's disease (PD). However, whether CMBs themselves are associated with PD is to be elucidated. METHODS: We analyzed the presence of CMBs using 3-Tesla brain magnetic resonance imaging in non-demented patients with PD and in age-, sex-, and hypertension-matched control subjects. PD patients were classified according to their motor subtypes: tremor-dominant, intermediate, and postural instability-gait disturbance (PIGD). Other cerebrovascular risk factors and small vessel disease (SVD) burdens were also evaluated. RESULTS: Two-hundred and five patients with PD and 205 control subjects were included. The prevalence of CMBs was higher in PD patients than in controls (16.1% vs. 8.8%; odds ratio [OR], 2.126; P = 0.019); CMBs in the lobar area showed a significant difference between PD patients and controls (11.7% vs. 5.9%; OR, 2.234; P = 0.032). According to the motor subtype, CMBs in those with PIGD type showed significant difference from controls with respect to the overall brain area (21.1% vs. 8.9%; OR, 2.759; P = 0.010) and lobar area (14.6% vs. 4.9%; OR, 3.336; P = 0.016). Among PD patients, those with CMBs had higher age and more evidence of SVDs than those without CMBs. CONCLUSION: We found that CMBs are more frequent in PD patients than in controls, especially in those with the PIGD subtype and CMBs on the lobar area. Further study investigating the pathogenetic significance of CMBs is required.

Validation of the Korean Version of the Scales for Outcomes in Parkinson's Disease-Sleep.

BACKGROUND: Sleep problems commonly occur in patients with Parkinson's disease (PD), and are associated with a lower quality of life. The aim of the current study was to translate the English version of the Scales for Outcomes in Parkinson's Disease-Sleep (SCOPA-S) into the Korean version of SCOPA-S (K-SCOPA-S), and to evaluate its reliability and validity for use by Korean-speaking patients with PD. METHODS: In total, 136 patients with PD from 27 movement disorder centres of university-affiliated hospitals in Korea were enrolled in this study. They were assessed using SCOPA, Hoehn and Yahr Scale (HYS), Unified Parkinson's Disease Rating Scale (UPDRS), Parkinson's Disease Sleep Scale 2nd version (PDSS-2), Non-motor Symptoms Scale (NMSS), Montgomery Asberg Depression Scale (MADS), 39-item Parkinson's Disease Questionnaire (PDQ39), Neurogenic Orthostatic Hypotension Questionnaire (NOHQ), and Rapid Eye Movement Sleep Behaviour Disorder Questionnaire (RBDQ). The test-retest reliability was assessed over a time interval of 10-14 days. RESULTS: The internal consistency (Cronbach's α-coefficients) of K-SCOPA-S was 0.88 for nighttime sleep (NS) and 0.75 for daytime sleepiness (DS). Test-retest reliability was 0.88 and 0.85 for the NS and DS, respectively. There was a moderate correlation between the NS sub-score and PDSS-2 total score. The NS and DS sub-scores of K-SCOPA-S were correlated with motor scale such as HYS, and non-motor scales such as UPDRS I, UPDRS II, MADS, NMSS, PDQ39, and NOHQ while the DS sub-score was with RBDQ. CONCLUSION: The K-SCOPA-S exhibited good reliability and validity for the assessment of sleep problems in the Korean patients with PD.

Photo-stability study of a solution-processed small molecule solar cell system: correlation between molecular conformation and degradation.

Solution-processed organic small molecule solar cells (SMSCs) have achieved efficiency over 11%. However, very few studies have focused on their stability under illumination and the origin of the degradation during the so-called burn-in period. Here, we studied the burn-in period of a solution-processed SMSC using benzodithiophene terthiophene rhodamine:[6,6]-phenyl C71 butyric acid methyl ester (BTR:PC71BM) with increasing solvent vapour annealing time applied to the active layer, controlling the crystallisation of the BTR phase. We find that the burn-in behaviour is strongly correlated to the crystallinity of BTR. To look at the possible degradation mechanisms, we studied the fresh and photo-aged blend films with grazing incidence X-ray diffraction, UV-vis absorbance, Raman spectroscopy and photoluminescence (PL) spectroscopy. Although the crystallinity of BTR affects the performance drop during the burn-in period, the degradation is found not to originate from the crystallinity changes of the BTR phase, but correlates with changes in molecular conformation - rotation of the thiophene side chains, as resolved by Raman spectroscopy which could be correlated to slight photobleaching and changes in PL spectra.

Loss of Nigral Hyperintensity on 3 Tesla MRI of Parkinsonism: Comparison With (123) I-FP-CIT SPECT.

BACKGROUND: The aim of this study was to investigate whether 3 Tesla susceptibility-weighted imaging can detect the alteration of substantia nigra hyperintensity in Parkinson's disease (PD), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP) and to assess the concordance between the loss of nigral hyperintensity on 3 Tesla susceptibility-weighted imaging and the nigrostriatal dopaminergic degeneration indicated by (123) I-2ß-carbomethoxy-3ß-(4-iodophenyl)-N-(3-fluoropropyl)-nortropane single photon emission computerized tomography. METHODS: Consecutive subjects with suspected parkinsonism were included, and clinical diagnosis was solidified during clinical follow-up. Two blinded neuroradiologists interpreted the nigral hyperintensity on susceptibility-weighted imaging. The performance of susceptibility-weighted imaging for detection of nigral hyperintensity loss was estimated on the basis of the clinical diagnosis and compared with single photon emission computerized tomography results. RESULTS: The study included 210 subjects (126 PD, 11 MSA, 11 PSP patients, 26 healthy controls, 36 disease controls). The presence or absence of nigral hyperintensity was accurately visualized in 112 PD, 7 MSA, and 11 PSP patients and 53 controls. We identified 16 false-negative cases and 11 false-positive cases. The sensitivity and specificity of susceptibility-weighted imaging were 88.8% and 83.6%, respectively. The concordance rate between susceptibility-weighted imaging and single photon emission computerized tomography was 86.2%. CONCLUSIONS: The loss of nigral hyperintensity on susceptibility-weighted imaging suggested nigrostriatal dopaminergic degeneration in a large portion of patients with parkinsonism, which was indicated by (123) I-2ß-carbomethoxy-3ß-(4-iodophenyl)-N-(3-fluoropropyl)-nortropane single photon emission computerized tomography. In consideration of false-negative and -positive cases, well-designed imaging protocols should be introduced to improve the performance of nigral hyperintensity imaging. © 2016 International Parkinson and Movement Disorder Society.