Ultra-bright, efficient and stable perovskite light-emitting diodes.

Metal halide perovskites are attracting a lot of attention as next-generation light-emitting materials owing to their excellent emission properties, with narrow band emission1-4. However, perovskite light-emitting diodes (PeLEDs), irrespective of their material type (polycrystals or nanocrystals), have not realized high luminance, high efficiency and long lifetime simultaneously, as they are influenced by intrinsic limitations related to the trade-off of properties between charge transport and confinement in each type of perovskite material5-8. Here, we report an ultra-bright, efficient and stable PeLED made of core/shell perovskite nanocrystals with a size of approximately 10 nm, obtained using a simple in situ reaction of benzylphosphonic acid (BPA) additive with three-dimensional (3D) polycrystalline perovskite films, without separate synthesis processes. During the reaction, large 3D crystals are split into nanocrystals and the BPA surrounds the nanocrystals, achieving strong carrier confinement. The BPA shell passivates the undercoordinated lead atoms by forming covalent bonds, and thereby greatly reduces the trap density while maintaining good charge-transport properties for the 3D perovskites. We demonstrate simultaneously efficient, bright and stable PeLEDs that have a maximum brightness of approximately 470,000 cd m-2, maximum external quantum efficiency of 28.9% (average = 25.2 ± 1.6% over 40 devices), maximum current efficiency of 151 cd A-1 and half-lifetime of 520 h at 1,000 cd m-2 (estimated half-lifetime >30,000 h at 100 cd m-2). Our work sheds light on the possibility that PeLEDs can be commercialized in the future display industry.

Clinical factors associated with delayed emergency department visit in intracranial traumatic brain injury: from a multicenter injury surveillance registry.

INTRODUCTION: Early diagnosis and intervention by visiting the emergency department (ED) are important for traumatic brain injury (TBI). We evaluate the factors associated with delayed ED visits in patients with intracranial TBI. METHODS: A retrospective multicenter observational study using the ED-based injury in-depth surveillance database (EDIIS) was designed. Patients with intracranial TBI with an alert mentality at ED presentation from 2014 to 2019 were enrolled. Patients were categorized into four groups according to ED visit time after injury (<1 h, 1-3 h, 3-12 h, and >12 h). ED visits after 12 h were defined as delayed ED visits. The factors associated with delayed ED visits were identified using multivariable logistic regression analysis. RESULTS: Among 15,620 patients with TBI enrolled in the final analysis, 2,190 (14.0%) visited the ED 12 h after injury. Multivariable analysis identified the following factors as independent predictors for delayed ED visit such as unintentionally struck by or against an object or unintentional fall as a trauma mechanism, injury during ordinary activities, indoor injury, injury during nighttime, winter season, combined subdural hemorrhage and epidural hemorrhage. CONCLUSION: In patients with intracranial TBI with an alert mentality, multiple factors related to patient demographics and injury characteristics were associated with the time interval from injury to ED visit.

Development of evidence-based consensus on critical issues in the management of patients with vitiligo: A modified Delphi study.

BACKGROUND/PURPOSE: Vitiligo remains a major challenge in dermatology. However, much of the treatment remains unclear, because little evidence is available. We sought to answer some critical questions pertaining to management of vitiligo patients. METHODS: A modified Delphi process among 31 vitiligo experts was conducted. A total of 12 clinical vitiligo treatment questions without clear answers were collected via a vote. To address each question, two members performed systematic literature reviews and prepared draft statements along with the levels of evidence and strength of recommendation. After reviewing the draft, all expressed their extent of agreement from 1 (strong disagreement) to 9 (strong agreement) for each item. The drafts were revised to reflect suggested comments. Discussion continued until all members agreed with the ultimate decision. RESULTS: The consensus process was completed after five rounds. We identified the best answers to 12 key questions, including issues on long-term phototherapy, systemic and topical corticosteroids, topical calcineurin inhibitors, immunosuppressants, excimer laser treatment, and surgical interventions. CONCLUSION: This consensus would complement current guidelines and aid both physician and patient decision-making in the treatment of vitiligo.

Regenerative efficacy of fibroblast growth factor for the treatment of aged vocal fold: From animal model to clinical application.

OBJECTIVES: We assessed fibroblast growth factor (FGF) regenerative efficacy in an aged vocal fold rat model and confirmed it in a prospective clinical trial. DESIGN, SETTING, AND PARTICIPANTS: For animal experiments, 48 Sprague-Dawley rats were divided into two groups: 24 six-month-olds (young group) and 24 twenty-four-month-olds (old group). FGF was injected once a week thrice into the left vocal fold of the old group, dividing them into two sub-groups (injected [left] and uninjected [right]). Additionally, we conducted a prospective clinical trial for 38 patients with aged atrophic vocal fold. MAIN OUTCOME MEASURES: A month post-injection, excised larynx from the three groups was subjected to comparative histopathological (ratio of relative lamina propria to total vocal fold) and mRNA expression analysis (of procollagen I, hyaluronic acid synthase (HAS)-2 and matrix metalloproteinase (MMP)-2) by real-time PCR. We performed perceptual, stroboscopic, acoustic aerodynamic test and Voice Handicap Index survey prior to and 1, 6 and 12 months after FGF injection. RESULTS: In rats, the relative lamina propria ratio increased after FGF injection. Procollagen I mRNA level decreased, whereas that of HAS-2 and MMP-2 increased significantly in the injected compared to the uninjected old group. Enrolled patients showed improved subjective and objective voice parameters after FGF injection, and these were maintained for a year. Potential side effects were not observed. CONCLUSIONS: Animal experiments and prospective clinical trial suggest that FGF injection to vocal fold can significantly improve voice quality until one year, without complications, and is effective for aged atrophic vocal fold treatment.

Effect of hypertension across the age group on survival outcomes in out-of-hospital cardiac arrest.

OBJECTIVE: There are few studies on the effects hypertension has on survival outcomes in out-of-hospital-cardiac arrest (OHCA) patients, although hypertension is a major risk factor for the incidence of cardiac arrest. This study aims to investigate whether hypertension is associated with survival outcomes in cardiac arrest patients across age groups. METHODS: This study was conducted using the national cardiac arrest registry of OHCA patients who survived to hospital admission from 2012 to 2016. The clinical histories of hypertension were obtained from patients' medical records. The endpoint was cerebral performance category (CPC) 1 and 2 (good CPC) and survival to discharge. Multivariable logistic regression analysis was performed on the data collected. The final model with an interaction term was evaluated to compare the effects of hypertension across age groups. RESULTS: A total 11,610 patients (61.0% hypertensive patients and 39.0% non-hypertensive patients) were included. The group over 80 years old with hypertension were more likely to have good neurologic recovery (AOR 2.53 [1.43-4.50]) and those under 65 years old with hypertension were more likely to survive to hospital discharge with statistical significance (AOR 1.19 [1.04-1.35]). CONCLUSIONS: Hypertension does not imply poor survival outcomes independently for all ages, as those over 80 years of age can have rather good neurological outcomes.

Dispatcher-Assisted Cardiopulmonary Resuscitation Program and Outcomes After Pediatric Out-of-Hospital Cardiac Arrest.

OBJECTIVES: A dispatcher-assisted bystander cardiopulmonary resuscitation (DA-BCPR) is expected to influence the outcomes of pediatric out-of-hospital cardiac arrest (OHCA). Our objective was to measure the effect size of a DA-BCPR on survival outcomes according to location of the event. METHODS: All emergency medical service treated OHCA patients younger than 19 years in Korea from January 2012 through December 2013 were analyzed. Patients with OHCA witnessed by emergency medical service providers and those with missing outcome information were excluded. Patients were categorized into the following categories: No-BCPR, BCPR without dispatcher assistance (BCPR-NDA), and BCPR-DA. The primary outcome was survival to hospital discharge. Multivariable logistic regression analysis was performed to calculate the adjusted odds ratios (AORs) and 95% confidence intervals (CIs) for outcomes by exposure group (reference, No-BCPR group) with and without an interaction term between exposure and location of arrest. RESULTS: A total of 1013 eligible patients were analyzed. Among these patients, 16.6% received BCPR-NDA, 23.2% received BCPR-DA, and 60.2% received no BCPR. After adjusting for potential confounders, compared with N0-BCPR group, AORs for survival were 1.79 (95% CI, 1.03-3.12) in BCPR group, 1.71 (95% CI, 0.85-3.46) in BCPR-NDA group, and 1.39 (95% CI, 0.72-2.69) in BCPR-DA group. The AORs for survival of BCPR-NDA and BCPR-DA in public location were 3.30 (95% CI, 1.12-9.72) and 2.95 (95% CI, 1.00-8.67), whereas BCPR-NDA and BCPR-DA in private locations were 1.62 (95% CI, 0.68-3.88) and 1.15 (95% CI, 0.53-2.51). CONCLUSION: The DA-CPR was associated with better outcomes in pediatric OHCA patients whose arrest occurred in public locations, but no improvement in outcomes was identified in patients whose arrest occurred at private locations.

Efficient terahertz generation in highly nonlinear organic crystal HMB-TMS.

We report on generation of strong and broadband terahertz (THz) pulses via collinearly phase-matched optical rectification of near-infrared femtosecond pulses in the organic nonlinear optical HMB-TMS (2-(4-hydroxy-3-methoxystyryl)-3-methylbenzo[d]thiazol-3-ium 2,4,6-trimethylbenzenesulfonate) single crystals which exhibit optimal molecular orientation and large macroscopic optical nonlinearity for efficient THz wave generation. Single-cycle THz pulses with a peak electric field strength of 0.66 MV/cm and a bandwidth from 0.1 to 5.4 THz are achieved from an HMB-TMS crystal with only a 2-mm clear aperture pumped by 1350 nm pulses at moderate fluences. The generated THz energy is about 1 µJ and the corresponding pump-to-THz energy conversion efficiency reaches 0.23%.

Generation of high-field terahertz pulses in an HMQ-TMS organic crystal pumped by an ytterbium laser at 1030 nm.

We present the generation of high-peak-electric-field terahertz pulses via collinear optical rectification in a 2-(4-hydroxy-3-methoxystyryl)-1-methilquinolinium-2,4,6-trimethylbenzenesulfonate (HMQ-TMS) organic crystal. The crystal is pumped by an amplified ytterbium laser system, emitting 170-fs-long pulses centered at 1030 nm. A terahertz peak electric field greater than 200 kV/cm is obtained for 420 µJ of optical pump energy, with an energy conversion efficiency of 0.26% - about two orders of magnitude higher than in common inorganic crystals collinearly pumped by amplified femtosecond lasers. An open-aperture Z-scan measurement performed on an n-doped InGaAs thin film using such terahertz source shows a nonlinear increase in the terahertz transmission of about 2.2 times. Our findings demonstrate the potential of this terahertz generation scheme, based on ytterbium laser technology, as a simple and efficient alternative to the existing intense table-top terahertz sources. In particular, we show that it can be readily used to explore nonlinear effects at terahertz frequencies.

Fluorescent Molecular Rotors for Viscosity Sensors.

Fluorescent molecular rotors (FMRs) can act as viscosity sensors in various media including subcellular organelles and microfluidic channels. In FMRs, the rotation of rotators connected to a fluorescent π-conjugated bridge is suppressed by increasing environmental viscosity, resulting in increasing fluorescence (FL) intensity. In this minireview, we describe recently developed FMRs including push-pull type π-conjugated chromophores, meso-phenyl (borondipyrromethene) (BODIPY) derivatives, dioxaborine derivatives, cyanine derivatives, and porphyrin derivatives whose FL mechanism is viscosity-responsive. In addition, FMR design strategies for addressing various issues (e.g., obtaining high FL contrast, internal FL references, and FL intensity-contrast trade-off) and their biological and microfluidic applications are also discussed.

Molecular Viscosity Sensors with Two Rotators for Optimizing the Fluorescence Intensity-Contrast Trade-Off.

A series of fluorescent molecular rotors obtained by introducing two rotational groups ("rotators"), which exhibit different rotational and electron-donating abilities, are discussed. Whereas the control molecular rotor, PH, includes a single rotator (the widely used phenyl group), the PO molecular rotors consist of two rotators (a phenyl group and an alkoxy group), which exhibit simultaneous strongly electron-donating and easy rotational abilities. Compared with the control rotor PH, PO molecular rotors exhibited one order of magnitude higher quantum yield (fluorescence intensity) and simultaneously exhibited significantly higher fluorescence contrast. These properties are directly related to the strong electron-donating ability and low energy barrier of rotation of the alkoxy group, as confirmed by dynamic fluorescence experiments and quantum chemical calculations. The PO molecular rotors exhibited two fluorescence relaxation pathways, whereas the PH molecular rotor exhibited a single fluorescence relaxation pathway. Cellular fluorescence imaging with PO molecular rotors for mapping cellular viscosity was successfully demonstrated.

Effect of National Implementation of Telephone CPR Program to Improve Outcomes from Out-of-Hospital Cardiac Arrest: an Interrupted Time-Series Analysis.

BACKGROUND: In cardiac arrest, the survival rate increases with the provision of bystander cardiopulmonary resuscitation (CPR), of which the initial response and treatment are critical. Telephone CPR is among the effective methods that might increase the provision of bystander CPR. This study aimed to describe and examine the improvement of neurological outcomes in individuals with out-of-hospital acute cardiac arrest by implementing the nationwide, standardized telephone CPR program. METHODS: Data from the emergency medical service-based cardiac arrest registry that were collected between 2009 and 2014 were used. The effectiveness of the intervention in the interrupted time-series study was determined via a segmented regression analysis, which showed the risk ratio and risk difference in good neurological outcomes before and after the intervention. RESULTS: Of 164,221 patients, 148,403 were analyzed. However, patients with unknown sex and limited data on treatment outcomes were excluded. Approximately 64.3% patients were men, with an average age of 63.7 years. The number of bystander CPR increased by 3.3 times (95% confidence interval [CI], 3.1-3.5) after the intervention, whereas the rate of good neurological outcomes increased by 2.6 times (95% CI, 2.3-2.9 [1.6%]; 1.4-1.7). The excess number was identified based on the differences between the observed and predicted trends. In total, 2,127 cases of out-of-hospital cardiac arrest (OHCA) after the intervention period received additional bystander CPR, and 339 cases of OHCA had good neurological outcomes. CONCLUSION: The nationwide implementation of the standardized telephone CPR program increased the number of bystander CPR and improved good neurological outcomes.

Effect of Dispatcher-Assisted Cardiopulmonary Resuscitation Program and Location of Out-of-Hospital Cardiac Arrest on Survival and Neurologic Outcome.

STUDY OBJECTIVE: We study the effect of a nationwide dispatcher-assisted cardiopulmonary resuscitation (CPR) program on out-of-hospital cardiac arrest outcomes by arrest location (public and private settings). METHODS: All emergency medical services (EMS)-treated adults in Korea with out-of-hospital cardiac arrests of cardiac cause were enrolled between 2012 and 2013, excluding cases witnessed by EMS providers and those with unknown outcomes. Exposure was bystander CPR categorized into 3 groups: bystander CPR with dispatcher assistance, bystander CPR without dispatcher assistance, and no bystander CPR. The endpoint was good neurologic recovery at discharge. Multivariable logistic regression analysis was performed. The final model with an interaction term was evaluated to compare the effects across settings. RESULTS: A total of 37,924 patients (31.1% bystander CPR with dispatcher assistance, 14.3% bystander CPR without dispatcher assistance, and 54.6% no bystander CPR) were included in the final analysis. The total bystander CPR rate increased from 30.9% in quarter 1 (2012) to 55.7% in quarter 4 (2014). Bystander CPR with and without dispatcher assistance was more likely to result in higher survival with good neurologic recovery (4.8% and 5.2%, respectively) compared with no bystander CPR (2.1%). The adjusted odds ratios for good neurologic recovery were 1.50 (95% confidence interval [CI] 1.30 to 1.74) in bystander CPR with dispatcher assistance and 1.34 (95% CI 1.12 to 1.60) in bystander CPR without it compared with no bystander CPR. For arrests in private settings, the adjusted odds ratios were 1.58 (95% CI 1.30 to 1.92) in bystander CPR with dispatcher assistance and 1.28 (95% CI 0.98 to 1.67) in bystander CPR without it; in public settings, the adjusted odds ratios were 1.41 (95% CI 1.14 to 1.75) and 1.37 (95% CI 1.08 to 1.72), respectively. CONCLUSION: Bystander CPR regardless of dispatcher assistance was associated with improved neurologic recovery after out-of-hospital cardiac arrest. However, for out-of-hospital cardiac arrest cases in private settings, bystander CPR was associated with improved neurologic recovery only when dispatcher assistance was provided.

Submillisievert Computed Tomography of the Chest in Contact Investigation for Drug-Resistant Tuberculosis.

Close contacts with infectious tuberculosis (TB) are persons at high risk for developing active disease. We preliminarily introduced submillisievert chest computed tomography (CT) scan (effective dose, 0.19-0.25 millisievert) in a contact investigation of multi-drug resistant (MDR)-TB. Baseline CT scan showed minimal nodules or branching opacities in two of six contacts. A two-month follow-up examination revealed a radiologic progression in contact 1, subsequently having the microbiologic diagnosis of MDR-TB at an asymptomatic early stage, whereas nodules transiently increased after 3 months in contact 2, followed by a decrease after one year. Contact 1 was cured after 1.5-year of anti-MDR-TB treatment. In conclusion, early identification of secondary MDR-TB is feasible with submillisievert chest CT scans in contact investigations of MDR-TB, minimizing of MDR-TB transmission and offering a favorable treatment outcome. This was a clinical trial study and was registered at www.ClinicalTrials.gov (Identifier: NCT02454738).

Light-emitting diodes downregulate cathelicidin, kallikrein and toll-like receptor 2 expressions in keratinocytes and rosacea-like mouse skin.

Cathelicidin (LL-37), Toll-like receptor 2 (TLR-2) and kallikreins (KLKs) are key inflammatory mediators in rosacea. Laser or light-based devices have been successfully used for rosacea. We investigated the effects of light-emitting diodes (LEDs) on LL-37, KLKs, TLR-2 and protease activity in cultured normal human epidermal keratinocytes (NHEKs) and rosacea-like mouse skin (RLMS). LL-37, KLK5, KLK7 and vitamin D receptor were induced by 1α, 25-dihydroxyvitamin D3 (VD3 ) and TLR-2 by Ad-CMV transfection in cultured NHEKs. NHEKs were subjected to LED irradiation at differing wavelengths (480-940 nm) and fluences (1-40 J/cm2 ). Inflammatory mediators were analysed with RT-PCR and real-time PCR and protease activity analysis and immunocytofluorescence staining were performed for NHEKs. Changes in RLMS induced by LL-37 peptide were evaluated with real-time PCR, immunohistochemical staining and enzyme-linked immunosorbent assay. In NHEKs, LED at 630 and 940 nm significantly attenuated LL37, KLK5 and TLR-2 mRNA expressions. Protease activity was significantly suppressed at 630, 850 and 940 nm. In the RLMS, LL-37, KLK5 and PAR-2 mRNA expressions significantly decreased at 24 and 48 hours after LED irradiation was performed three times at 630 and 940 nm. mCAMP and IL-8 protein levels and protease activity after LED irradiation were lower than those in RLMS control groups. LED at 630 and 940 nm downregulated TLR-2, KLK5 and LL-37 expressions and protease activity in NHEK and RLMS. Thus, LEDs may be promising for rosacea treatment. However, clinical trials are required for further study.

Alcohol Intake and Reduced Mortality in Patients with Traumatic Brain Injury.

BACKGROUND: The purpose of our study was to determine whether alcohol intake influences short-term mortality in patients with traumatic brain injury (TBI), using a comprehensive trauma database. METHODS: We collected data from 7 emergency departments (EDs) between June 1, 2008 and May 31, 2010, using the same data form. Cases were included if they met the following criteria: (i) older than 15 and (ii) injuries including TBI. Demographics and outcomes were compared between patients with and without alcohol intake. We present the risk of mortality using hazard ratios and 95% confidence intervals. RESULTS: A total of 76,596 trauma patients visited the EDs during the study period; 12,980 patients were older than 15 and had TBI. There were 4,009 (30.9%) patients in the alcohol-intake group, of whom 3,306 (82.5%) patients were male, 1,450 (36.2%) patients were moved by ambulance, and 1,218 (30.4%) patients' injuries were intentional. The most frequent injury mechanism was falling down with alcohol intake and blunt injury without alcohol intake. Mortality rate was 1.0% with alcohol intake and 2.0% without alcohol intake. After adjusting for all factors related to mortality, the hazard ratio of mortality was 0.72 in the alcohol-intake group. CONCLUSIONS: Mortality rate due to TBI in the alcohol-intake group appears to be lower compared to that in the no-alcohol-intake group after adjusting for main confounding variables.

The association between acute alcohol consumption and discharge against medical advice of injured patients in the ED.

PURPOSES: A paucity of data exists on the prevalence and predictors of discharging injured patients against medical advice from emergency departments. The aim of this study is to investigate the association between acute alcohol use and being discharged against medical advice. METHODS: We performed a prospective, observational study of injured patients enrolled into the Korean Centers for Disease and Prevention injury surveillance program in 7 tertiary, academic, and teaching hospitals from June 1, 2008, to November 31, 2011. Injured patients were assigned to 1 of 3 groups: discharged against medical advice, regular discharge, and transferred or admitted. Multivariable logistic regression models were used to analyze the association between acute alcohol use and being discharged against medical advice. RESULTS: A total of 125,327 patients were enrolled, and 3473 (2.8%) were discharged against medical advice. The proportion of acute alcohol use was significantly higher among the patients who were discharged against medical advice (40.1%) than the regular discharged (16.6%) or transferred/admitted (15.5%) patients. In a regression model, acute alcohol use increased the risk of being discharged against medical advice (adjusted odds ratio, 1.86; 95% confidence interval, 1.70-2.03). In addition, we identified the interaction between acute alcohol use and intention of injury. Acute alcohol use had a significant association with the discharge against medical advice with the unintentional injury (adjusted odds ratio, 2.56; 95% confidence interval, 2.30-2.84). CONCLUSION: Patients with acute alcohol use before sustaining an injury are at increased risk of being discharged against medical advice from the emergency departments.

Age effects on case fatality rates of injury patients by mechanism.

BACKGROUND: Case fatality from injury increases exponentially with age. The objective of this study is to identify age effects on case fatality of injury patients by injury mechanism. METHODS: This is an observational study using the Emergency Department-based Injury In-depth Surveillance data from 2007 to 2012. Eligibility was all injured patients, excluding those with unknown information for age, disposition after emergency department or admission, or injury mechanism. End point of this study was inhospital mortality. Injury mechanism was categorized into road transport injury (RTI), fall, collision, cut/pierce, burn, poisoning, and miscellaneous. Case fatality ratio was calculated to evaluate age effects on case fatality by injury mechanism and gender. RESULT: Among 927011 injury patients, a total of 924755 patients were analyzed. Total case fatality rate was 0.9%, and rates by injury mechanisms were 4.4% in poisoning, 2.1% in RTI, and 0.8% in fall. By age and gender, the highest crude case fatality rate was 19.74% observed in older than 80-year-old men with poisoning. Case fatality ratios in both genders increased by age from 60- to 69-, 70- to 79-, to older than 80-year-old patients; ratios by injury mechanisms were 13.71, 20.76, and 22.29 (male) and 7.21, 11.18, and 13.05 (female) in poisoning; 5.46, 9.30, and 14.13 (male) and 3.90, 7.96, and 12.08 (female) in RTI; 1.22, 1.52, and 2.02 (male) and 1.14, 2.15, and 6.42 (female) in burn. CONCLUSIONS: Case fatality rates of injury increased with age; however, the trends in increase differed by injury mechanisms and gender. Strategies for injury prevention and decreasing mortality should consider the age effects on case fatality of different injury mechanisms.

Unusual Transformation from a Solvent-Stabilized 1D Coordination Polymer to a Metal-Organic Framework (MOF)-Like Cross-Linked 3D Coordination Polymer.

An unusual 1D-to-3D transformation of a coordination polymer based on organic linkers containing highly polar push-pull π-conjugated side chains is reported. The coordination polymers are synthesized from zinc nitrate and an organic linker, namely, 2,5-bis{4-[1-(4-nitrophenyl)pyrrolidin-2-yl]butoxy}terephthalic acid, which possesses highly polar (4-nitrophenyl)pyrrolidine groups, with high dipole moments of about 7 D. The coordination polymers exhibit an unusual transformation from a soluble, solvent-stabilized 1D coordination polymer into an insoluble, metal-organic framework (MOF)-like 3D coordination polymer. The coordination polymer exhibits good film-forming ability, and the MOF-like films are insoluble in conventional organic solvents.

Comparison of short- and long-term outcomes of an early experience with robotic and laparoscopic-assisted resection for rectal cancer.

BACKGROUND/AIMS: Robotic surgery is increasingly used for rectal cancer. We compared the short- and long-term outcomes between robotic- and laparoscopic-assisted resection for rectal cancer. METHODOLOGY: A retrospective chart review was performed between 2006 and 2010. RESULTS: Seventeen robotic and 61 laparoscopic surgeries were performed consecutively. Median follow-up time was 58.2 months. No operation was converted to open surgery. No difference was observed between the groups for types of operations, diverting ileostomy rate, operation time, blood loss, and postoperative hospital stay, tumor diameter, distal margin, circumferential margin, tumor stage, differentiation, lymphovascular, or perineural invasion. However, the number of harvested lymph nodes was higher in the robot than that in the laparoscopy group (p = 0.017). Overall morbidity and reoperation rates were similar between the groups. The 5-yr overall and disease-free survival rates of all patients were 82.5% and 81.3%, respectively. The 5-yr overall and disease-free survival rates of the robotic and the laparoscopy groups were 94.1% and 79.7% (p = 0.241), and 94.1% and 77.9% (p = 0.159), respectively. CONCLUSIONS: Robot-assisted resection for rectal cancer resulted in harvesting more lymph nodes without increasing morbidity and showed a comparable survival rate, compared with those of laparoscopy.

Experimental analysis of the liquid-feeding mechanism of the butterfly Pieris rapae.

The butterfly Pieirs rapae drinks liquid using a long proboscis. A high pressure gradient is induced in the proboscis when cibarial pump muscles contract. However, liquid feeding through the long proboscis poses a disadvantage of high flow resistance. Hence, butterflies may possess special features to compensate for this disadvantage and succeed in foraging. The main objective of this study is to analyze the liquid-feeding mechanism of butterflies. The systaltic motion of the cibarial pump organ was visualized using the synchrotron X-ray imaging technique. In addition, an ellipsoidal pump model was established based on synchrotron X-ray micro-computed tomography. To determine the relationship between the cyclic variation of the pump volume and the liquid-feeding flow, velocity fields of the intake flow at the tip of the proboscis were measured using micro-particle image velocimetry. Reynolds and Womersley numbers of liquid-feeding flow in the proboscis were ~1.40 and 0.129, respectively. The liquid-feeding flow could be characterized as a quasi-steady state laminar flow. Considering these results, we analyzed the dimensions of the feeding apparatus on the basis of minimum energy consumption during the liquid-feeding process. The relationship between the proboscis and the cibarial pump was determined when minimum energy consumption occurs. As a result, the volume of the cibarial pump is proportional to the cube of the radius of the proboscis. It seems that the liquid-feeding system of butterflies and other long-proboscid insects follow the cube relationship. The present results provide insights into the feeding strategies of liquid-feeding butterflies.