Terahertz asymmetric metallic hole arrays with polarization-independent quasi-bound states in the continuum for membrane sensing.

Resonances with both high-quality factor and polarization-independent characteristics are highly desirable for terahertz (THz) sensing. Here, THz sensors based on asymmetric metallic hole arrays (AMHAs) are experimentally demonstrated. Such sensors consisting of four-hole arrays support polarization-independent quasi-bound states in the continuum (BICs). The induced quasi-BIC presents a quality factor exceeding 2000, which enables enhanced sensing for thin membranes. Results show that the frequency shift is 97.5 GHz for the 25-µm thick polyimide (PI), corresponding to a sensitivity of 147.7 GHz/RIU. The sensing performance strongly relates to the enhanced field originating from sharp quasi-BICs. A maximum field enhancement of 15.88 in contrast to the incident field is achieved. When the PI thickness is large than the decay length of enhanced fields, the interaction strength of field-PI becomes weak, resulting in a saturation effect for the shift of quasi-BICs. The proposed sensor possessing polarization-independent quasi-BICs has great potential for practical sensing applications in real-time chemical and biomolecular.

Texture and color enhancement imaging improves the visibility of gastric neoplasms: clinical trial with image catalogue assessment using conventional and newly developed endoscopes.

BACKGROUND: Texture and color enhancement imaging (TXI) enhances the changes in endoscopic features caused by gastric neoplasms, such as redness/whiteness and elevation/depression. This study aimed to demonstrate the effectiveness of TXI in improving the visibility of gastric neoplasms compared with white light imaging (WLI) using conventional (CE) and newly developed endoscopes (NE). METHODS: We recruited patients who were histologically diagnosed with gastric neoplasms; endoscopy was performed, and gastric neoplasms photographed using three imaging modalities, including WLI, TXI mode 1 (TXI-1) and TXI mode 2 (TXI-2). Two different endoscopes (CE and NE) were used for the same patients. Six endoscopists provided the visibility scale scores ranging from 1 (poor) to 4 (excellent) for gastric neoplasms. The primary outcome was the visibility scale scores based on each modality and endoscope. The secondary outcome was the identification of factors including H. pylori infection, atrophy, location, size, morphology, histological diagnosis and intestinal metaplasia that affect the differences in visibility scale scores between TXI-1/TXI-2 and WLI. RESULTS: Fifty-two gastric neoplasms were analyzed. The mean visibility scale scores with the NE were 2.79 ± 1.07, 3.23 ± 0.96 and 3.14 ± 0.92 for WLI, TXI-1 and TXI-2, respectively. The mean visibility scales with the CE were 2.53 ± 1.10, 3.04 ± 1.05 and 2.96 ± 1.92 for WLI, TXI-1 and TXI-2, respectively. For both endoscopes, significant differences were observed in visibility scale scores between WLI and TXI-1 (p < 0.001) and between WLI and TXI-2 (p < 0.001). The visibility scale scores of NE were superior to those of CE in all modalities. In the secondary outcome, there was no factor affected the differences of visibility scale scores between TXI-1/TXI-2 and WLI. CONCLUSIONS: This study demonstrated that TXI-1 and TXI-2 enhanced the visibility scale scores of gastric neoplasms compared with that of WLI. Moreover, newly developed endoscope has the potential to improve visibility compared to conventional endoscope. TRIAL REGISTRATION: This study was registered with the University Hospital Medical Information Network (UMIN000042429, 16/11/2020).

Effect of storage temperature and flash-freezing on salivary microbiota profiles based on 16S rRNA-targeted sequencing.

The sample storage environment affects gut microbial profiles as assessed using 16S rRNA sequencing. However, the influence of storage condition on human salivary microbial profiles has not been well characterized. Here, we performed an observational study to assess the robustness of microbiota profiles in three different storage environments (-80°C after flash-freezing, -80°C, and -15°C; all for 14 days) compared to immediate DNA extraction using the MiSeq Illumina platform. Notably, the 16S rRNA V1-V2 region amplicon sequencing revealed no difference in microbiota profiles between the immediate extraction and each of three storage conditions. An almost perfect correlation was shown between the immediate extraction and the -15°C storage group for relative abundance at the genus and operational taxonomic unit levels. The intraindividual UniFrac distances among storage methods were significantly shorter than those of interindividual distances. None of the amount of extracted DNA, the α-diversity indices, or the relative abundance at the phylum/genus/operational taxonomic unit level differed among storage methods. These findings indicate that a storage temperature of -15°C without flash-freezing may be optimal in terms of cost advantage and simplicity in 16S rRNA sequencing-based salivary microbial research.

Terahertz high-Q quasi-bound states in the continuum in laser-fabricated metallic double-slit arrays.

A laser-fabricated metallic resonator based on a double-slit array (DSA) is numerically and experimentally demonstrated at terahertz frequencies. Such free-standing resonators achieve a sharp resonance with high quality (Q) factor, arising from a distortion of symmetry-protected bound states in the continuum (BIC). By breaking the structural symmetry of DSAs, the BIC with infinite Q-factor can be transformed into quasi-BICs, and the Q-factors decrease gradually as the asymmetry parameter increases. We analyzed the influence of the imperfection in experimental samples such as the round edge and the trapezoid shape on the transmission properties of DSAs. Different from the DSAs composed of ideal perfect electrical conductors, copper DSAs show lower Q-factor because of the Ohmic loss. The effect of metal thickness on the quasi-BICs for DSAs is also investigated. Results exhibit that thinner resonators can achieve sharper quasi-BICs. These findings suggest that such metallic resonators with high Q-factors have great potential for practical applications in electromagnetic wave filtering and biomolecular sensing.

Polymer-coated moth-eye hybrid structure for broadband antireflection in the terahertz region.

A hybrid antireflective structure (ARS) is proposed for enhancing the transmittance of terahertz (THz) waves. This hybrid ARS was made by attaching a polymer-based two-layer coating onto a moth-eye structure on a silicon (Si) substrate. The measured power reflectance of this hybrid ARS remained below 6% in the frequency range of 0.6-2.5 THz, corresponding to the simulated results. The total power reflectance from 0.1 to 2.5 THz was 20% that of the unprocessed Si surface. Besides exhibiting a broadband AR characteristic, this hybrid ARS inherited the cleanable flat surface from the coating structure, which also acts as a protective shield for the moth-eye structures. This high-transmittance, cleanable, flat antireflective surface can not only improve the performance of numerous THz components but also promote the applications of THz waves in daily life.

Femtosecond PLD-grown YF3 nanoparticle thin films as improved filterless VUV photoconductive detectors.

A photoconductive detector (PCD) responding only to vacuum ultraviolet (VUV) radiations below 180 nm without any filter was fabricated using an yttrium fluoride (YF3) thin film grown by femtosecond (fs) laser pulsed laser deposition (PLD). The structural morphology (particle size and surface roughness) of the thin film was improved using a low laser fluence and a high substrate temperature during the fabrication. The smallest average particle size achieved was 159 nm with a roughness of 37 nm at a laser fluence of 13.5 J cm-2 and a substrate temperature of 400 °C. The resistances for the dark current of the PCD increased from 10 TΩ to 680 TΩ using YF3 thin films with a smaller average nanoparticle diameter of 159 nm rather than 330 nm. The time response of the PCD to a VUV flash lamp emitting at 170 nm showed that a small average nanoparticle diameter results to a fast response time. By covering the Al electrode pairs with another fs PLD-grown YF3 film, the influence of external photoelectric effect was suppressed and the response wavelength edge decreased from 280 nm to 180 nm without any filter. The filterless PCD is expected to enhance the use of fluoride thin films in conjunction with VUV light sources for various scientific and industrial applications.

Blood group O is a risk factor for delayed post-polypectomy bleeding.

BACKGROUND: Blood group O of ABO blood group system is considered as a risk factor for various bleeding events, but the relationship with endoscopic treatment-associated bleeding has yet to be investigated. This study aimed to evaluate whether blood group O is associated with delayed bleeding after colorectal endoscopic resection. METHODS: This was a retrospective observational study based on medical records at four university hospitals in Japan. We reviewed the records for consecutive patients who underwent colorectal endoscopic resection from January 2014 through December 2017. The primary outcome was the incidence of delayed bleeding, defined as hematochezia or melena, requiring endoscopy, transfusion, or any hemostatic intervention up to 28 days after endoscopic resection. Multivariate logistic regression analysis was performed to adjust the impact of blood group O on the delayed bleeding. RESULTS: Among 10,253 consecutive patients who underwent colorectal endoscopic resection during the study period, 8625 patients met the criteria. In total, delayed bleeding occurred in 255 patients (2.96%). The O group had significantly more bleeding events compared with the non-O group (A, B, and AB) (relative risk, 1.62 [95% confidence interval, 1.24-2.10]; P < 0.001). In multivariate logistic regression analysis, blood group O remained an independent risk factor for the bleeding (adjusted odds ratio, 1.60 [95% confidence interval, 1.18-2.17]; P = 0.002). CONCLUSIONS: Blood group O was associated with an increased risk of delayed bleeding in patients undergoing colorectal endoscopic resection. Preoperative screening for ABO blood group could improve risk assessments.

Intra-abdominal pressure during endoscopic full-thickness resection comparing manual and automatic control insufflation: a block-randomized porcine study.

BACKGROUND AND STUDY AIMS: An automatic carbon dioxide (CO2) insufflating system (SPACE) was developed to stabilize intra-lumenal pressure (ILP) during endoscopic interventions. This study investigated whether SPACE could improve the control and monitoring of extra-lumenal intra-abdominal pressure (IAP) after establishing a perforation during endoscopic full-thickness resection (EFTR) of the gastric wall in porcine models. MATERIALS AND METHODS: After first establishing the optimal preset pressure for gastric EFTR in four pigs, we compared IAP dynamics during EFTR between manual insufflation and SPACE using a block-randomized study (n = 10). IAP was percutaneously monitored and plotted on a timeline graph every 5 s. The maximal IAP and the area under the IAP curve exceeding 10 mmHg (AUC≥10 mmHg) were compared between groups, with the agreement between IAP and endolumenally monitored ILP also analyzed for animals in the SPACE group. RESULTS: In the first study, 8 mmHg was identified as the most preferable preset pressure after establishment of the perforation. In the randomized study, the mean maximal IAP in the SPACE group was significantly lower than that in the manual insufflation group (11.0 ± 2.0 mmHg vs. 17.0 ± 3.5 mmHg; P = 0.03). The mean AUC≥10 mmHg was also significantly smaller in the SPACE group. Bland-Altman analysis demonstrated agreement between IAP and ILP within a range of ± 1.0 mmHg. CONCLUSIONS: SPACE could be used to control and safely monitor IAP during gastric EFTR by measuring ILP during perforation of the gastric wall.

Femtosecond-laser-fabricated periodic tapered structures on a silicon substrate for terahertz antireflection.

In this research, terahertz (THz) antireflective structures tapered with several profiles (linear, exponential, Klopfenstein) were modeled for high-resistivity silicon and theoretically evaluated using a high-frequency electromagnetic field simulation (HFSS). Their antireflective characteristics are greatly affected by the profiles. One-dimensional periodic tapered THz antireflective structures with different profiles were also fabricated on high-resistivity silicon using femtosecond laser processing. Their antireflective characteristics were experimentally evaluated by standard THz time-domain spectroscopy and modeled by HFSS for reference. The experimental results are in good agreement with the simulations, which showed that the Fresnel reflection reduces to almost zero over a band broader than 1 THz.

Size control and vacuum-ultraviolet fluorescence of nanosized KMgF3 single crystals prepared using femtosecond laser pulses.

We fabricated nanosized KMgF3 single crystals via a dry pulsed laser ablation process using femtosecond laser pulses. The sizes, shapes, and crystallographic properties of the crystals were evaluated by transmission electron microscopy (TEM). Almost all of the particles were spherical with diameters of less than 100 nm, and they were not highly agglomerated. Selected-area electron diffraction and high-resolution TEM analyses showed that the particles were single crystals. Particle diameter was controlled within a wide range by adjusting the Ar ambient gas pressure. Under low gas pressures (1 and 10 Pa), relatively small particles (primarily 10 nm or less) were observed with a high number density. With increasing pressure, the mean diameter increased and the number density drastically decreased. Vacuum-ultraviolet cathodoluminescence was observed at 140-230 nm with blue shift and broadening of spectrum.

[A Case Report of Continuous Bleeding due to Severe Skin Metastases of Breast Cancer Successfully Treated Using Mohs Paste].

We report a case of severe skin metastases of advanced right breast cancer in an 84-year-old woman. The tumor (T4bN3cM0, Stage III C)was resected in June 2011(BT+AX)after blood transfusion for severe anemia. Radiotherapy to the right chest wall and supraclavicular lymph nodes was performed, and adjuvant hormonal therapy was administered. Local recurrences in the skin of the right chest wall appeared and were resected in December 2011. Nine months later, continuous bleeding from the progressed, widespread skin metastases needed recurrent blood transfusion. After using Mohs paste twice, the bleeding stopped almost completely. Mohs paste was very useful for stopping bleeding in locally advanced, unresectable skin metastasis.

Vacuum ultraviolet field emission lamp consisting of neodymium ion doped lutetium fluoride thin film as phosphor.

A vacuum ultraviolet (VUV) field emission lamp was developed by using a neodymium ion doped lutetium fluoride (Nd(3+) : LuF3) thin film as solid-state phosphor and carbon nanofiber field electron emitters. The thin film was synthesized by pulsed laser deposition and incorporated into the lamp. The cathodoluminescence spectra of the lamp showed multiple emission peaks at 180, 225, and 255 nm. These emission spectra were in good agreement with the spectra reported for the Nd(3+) : LuF3 crystal. Moreover, application of an acceleration voltage effectively increased the emission intensity. These results contribute to the performance enhancement of the lamp operating in the VUV region.

[A case of cardiac tamponade due to pericarditis carcinomatosa of breast cancer successfully treated via pericardiocentesis and systemic chemo-endocrine therapy].

We report a case of lung and bone metastases of right advanced breast cancer in a 33-year-old woman. Her breast cancer (T4bN1M1, StageIV)was resected in December 2003 (mastectomy [BT] plus axillary lymph node dissection [AX]) after local arterial infusion therapy and subsequent systemic chemo-endocrine therapy was initiated and continued. In June 2007, a computed tomography (CT) scan revealed cardiac tamponade due to pericarditis carcinomatosa. Pericardiocentesis was performed, and the bloody effusion was drained immediately. Subsequently, the sysytemic chemo-endocrine therapy was modified. In 2009, multiple cerebellar metastases were discovered and treated via whole brain irradiation. In 2010, multiple liver metastases appeared, and they were treated by intravenous (IV) administration of nab-paclitaxel. In 2011, superior vena cava syndrome appeared gradually, and it was treated via venous metallic stenting. In 2012, epidural spinal cord compression appeared gradually, and it was treated via irradiation. In November 2012, the patient died because of lymphangitis carcinomatosa; her prognosis was good, as it was approximately 5 years after the pericardiocentesis.

Diagnostic Performance of a Novel Ultra-Thin Endoscopy under Narrow-Band Imaging for Superficial Squamous Cell Carcinoma of the Pharynx and Esophagus.

This study aimed to evaluate the diagnostic utility of the ultra-thin endoscope (UTE) for superficial squamous cell carcinoma (SSCC) compared to magnifying endoscopy (ME) under narrow-band imaging. Participants underwent endoscopic examination, and images of pharyngeal and esophageal SCCs, as along with suspicious SSCC lesions, were collected using UTE and ME on the same day. Three image catalogs (UTE, ME-1, and ME-2) were created and reviewed by three expert endoscopists. ME-1 and ME-2 contained the same endoscopic images. The primary endpoint was the intra-observer agreement for diagnosing SCC. Eighty-six lesions (SCC = thirty-nine, non-SCC = forty-seven) in 43 participants were identified. The kappa values for the intra-observer agreement between UTE and ME-1 vs. the control (ME-1 vs. ME-2) were 0.74 vs. 0.84, 0.63 vs. 0.76, and 0.79 vs. 0.88, respectively. The accuracies for diagnosing SCC by UTE and ME-1 were 87.2% vs. 86.0%, 78.0% vs. 73,2%, and 75.6 vs. 82.6%, respectively, with no significant differences (p > 0.05). The rates of lesions that were diagnosed with confidence by UTE and ME-1 were 30.2% vs. 27.9%, 55.8% vs. 62.8%, and 58.1% vs. 55.8%, respectively. UTE demonstrates substantial diagnostic performance for SSCC in the pharynx and esophagus.

Static Hydrophobic Cuprous Oxide Surface Fabricated via One-Step Laser-Induced Oxidation of a Copper Substrate.

In this study, we developed a one-step method for fabricating hydrophobic surfaces on copper (Cu) substrates. Cuprous oxide (Cu2O) with low free energy was successfully formed after low-fluence laser direct irradiation. The formation of Cu2O enhanced the hydrophobicity of the Cu substrate surface, and the contact angle linearly increased with the proportion of Cu2O. The Cu2O fabricated by low-fluence laser treatment showed the same crystal plane orientation as the pristine Cu substrate, implying an epitaxial growth of Cu2O on a Cu substrate.

Sarcopenia Is a Prognostic Factor in Patients Undergoing Percutaneous Endoscopic Gastrostomy.

(1) Background: Percutaneous endoscopic gastrostomy (PEG) is a widely used long-term enteral nutrition method, but little is known about the associated prognostic factors in patients with PEG. Sarcopenia, a condition characterized by a loss of skeletal muscle mass, increases the risk of developing various gastrointestinal disorders. Yet, the relationship between sarcopenia and the prognosis after PEG remains unclear. (2) Methods: We conducted a retrospective study of patients who underwent PEG consecutively from March 2008 to April 2020. We analyzed preoperative sarcopenia and the prognosis of patients after PEG. We defined sarcopenia as a skeletal muscle index at the level of the third lumbar vertebra of ≤29.6 cm2/m2 for women and ≤36.2 cm2/m2 for men. Cross-sectional computed tomography images of skeletal muscle at the level of the third lumbar vertebra were evaluated using DICOM image analysis software (OsiriX). The primary outcome was the difference in overall survival after PEG based on the status of sarcopenia. We also performed a covariate balancing propensity score matching analysis. (3) Results: Of 127 patients (99 men, 28 women), 71 (56%) were diagnosed with sarcopenia, and 64 patients died during the observation period. The median follow-up period did not differ between patients with and without sarcopenia (p = 0.5). The median survival time after PEG was 273 days in patients with sarcopenia and 1133 days in those without (p < 0.001). Cox proportional hazard model analyses identified three factors that were significantly associated with overall survival: sarcopenia (adjusted hazard ratio [HR]: 2.9, 95% confidence interval [CI]: 1.6-5.4, p < 0.001), serum albumin level (adjusted HR: 0.34, 95% CI: 0.21-0.55, p < 0.001) and male sex (adjusted HR: 2.0, 95% CI: 1.1-3.7, p = 0.03). Propensity score-matched analysis (n = 37 vs. 37) showed that the survival rate was lower in the sarcopenia group than in the non-sarcopenia group (at 90 days: 77% (95% CI, 59-88) vs. 92% (76-97), at 180 days: 56% (38-71) vs. 92% (76-97), and at one year: 35% (19-51) vs. 81% (63-91), p = 0.0014). (4) Conclusions: Sarcopenia was associated with poor prognosis in patients having undergone PEG.

Carbonization of a Molybdenum Substrate Surface and Nanoparticles by a One-Step Method of Femtosecond Laser Ablation in a Hexane Solution.

Molybdenum carbides (MoC and Mo2C) are being reported for various applications, for example, catalysts for sustainable energies, nonlinear materials for laser applications, protective coatings for improving tribological performance, and so on. A one-step method for simultaneously fabricating molybdenum monocarbide (MoC) nanoparticles (NPs) and MoC surfaces with a laser-induced periodic surface structure (LIPSS) was developed by using pulsed laser ablation of a molybdenum (Mo) substrate in hexane. Spherical NPs with an average diameter of 61 nm were observed by scanning electron microscopy. The X-ray diffraction pattern and electron diffraction (ED) pattern results indicate that a face-centered cubic MoC was successfully synthesized for the NPs and on the laser-irradiated area. Notably, the ED pattern suggests that the observed NPs are nanosized single crystals, and a carbon shell was observed on the surface of MoC NPs. The X-ray diffraction pattern of both MoC NPs and LIPSS surface indicates the formation of FCC MoC, agreeing with the results of ED. The results of X-ray photoelectron spectroscopy also showed the bonding energy attributed to Mo-C, and the sp2-sp3 transition was confirmed on the LIPSS surface. The results of Raman spectroscopy have also supported the formation of MoC and amorphous carbon structures. This simple synthesis method for MoC may provide new possibilities for preparing Mo x C-based devices and nanomaterials, which may contribute to the development of catalytic, photonic, and tribological fields.

[A case report of liver metastasis of breast cancer successfully treated by hepatic arterial infusion of docetaxel and systemic administration of nab-paclitaxel].

We report the case of an effectively treated 50-year-old woman with liver metastasis of left breast cancer. Her breast cancer (T2N0M0, Stage IIA) was resected in November 1998 (radical mastectomy+axillary lymph nodes dissection). After this operation, tamoxifen(TAM 20 mg daily) was administered. In February 2002, a solitary liver metastasis(S5, 4 cm in diameter) was found by computed tomography(CT) scan. Hepatic arterial infusion of docetaxel(DOC 20 mg weekly)was started. In March 2003, the solitary liver metastasis had become smaller and showed partial remission (PR), but DOC intravenous injection(iv) therapy(40 mg weekly) was started because lung metastases appeared. Therefore, epirubicin+ cyclophosphamide therapy, DOC ia therapy (120 mg triweekly), and anastrozole (1 mg daily) were continued. However, in March 2005, she refused chemotherapy. In January 2011, a CT scan showed progressive disease of multiple liver and lung metastases. Nab-paclitaxel(PTX) iv therapy(400 mg triweekly) and exemestane(25 mg daily) were administered. In March 2012, a CT scan showed PR of the metastatic breast cancer. She has continued to receive nab-PTX iv therapy as an outpatient.

International remote collaboration enabled inaugural endoscopic sleeve gastroplasty in Japan.

Obesity causes multiple conditions such as type 2 diabetes, cardiovascular disease, and so on, and an intervention is needed for controlling weight and improving metabolic syndrome. However, the effectiveness of lifestyle interventions and pharmacotherapy are restrictive for losing weight. Endoscopic sleeve gastroplasty (ESG) was developed as a new therapy, picking the best of both medication and surgery, less invasive and more effective. Recently, ESG is gradually spreading in Western countries, but there is Case report doesn't need conclusion/result for Japanese patients. We herein reported the first clinical case of ESG in Japan. Given the situation of the pandemic of COVID-19, we could not invite a proctor from Western countries and receive the instruction of the device setting and maneuver face to face. Thus, we conducted the training for device setting, maneuver, and operation under a web-based international remote collaboration. Eventually, we completed ESG without an adverse event. We could prove this web-based proctor system was useful through the introduction of ESG in Japan. The international remote collaboration could become a new normal even in the endoscopy field post-COVID-19 era.

The Advantage of Immunohistochemical Staining for Evaluating Lymphovascular Invasion Is Limited for Patients with Esophageal Squamous Cell Carcinoma Invading the Muscularis Mucosa.

The cumulative metastasis rate of esophageal squamous cell carcinoma (ESCC) pathologically invading the muscularis mucosae (pT1a-MM), based on lymphovascular invasion (LVI) evaluated by immunohistochemical (IHC) staining is unknown. This retrospective study included patients with endoscopically resected pT1a-MM ESCC. The primary endpoint was the metastasis rate of pT1a-MM based on LVI, evaluated using IHC and additional prophylactic therapy. The secondary endpoint was the identification of independent factors for metastasis based on lesion characteristics. The prognosis was also analyzed considering the impact of head and neck cancer. A total of 104 patients were analyzed, with a median follow-up of 74 months. The positive rate for LVI was 43.3% (45/104). In 33 patients, IHC was not performed at the time of clinical evaluation, 8 of whom exhibited LVI. However, these patients did not exhibit metastasis. The metastasis rates of patients without LVI, those with LVI and additional therapy, and those with LVI without additional therapy were 5.1%, 20.8%, and 0%, respectively. Lesion size ≥ 25 mm was the only independent factor for metastasis in multivariate analysis. The advantage of IHC for determining additional prophylactic therapy is limited for patients with pT1a-MM ESCC.