Crystallization kinetics of atomic crystals revealed by a single-shot and single-particle X-ray diffraction experiment.

Crystallization is a fundamental natural phenomenon and the ubiquitous physical process in materials science for the design of new materials. So far, experimental observations of the structural dynamics in crystallization have been mostly restricted to slow dynamics. We present here an exclusive way to explore the dynamics of crystallization in highly controlled conditions (i.e., in the absence of impurities acting as seeds of the crystallites) as it occurs in vacuum. We have measured the early formation stage of solid Xe nanoparticles nucleated in an expanding supercooled Xe jet by means of an X-ray diffraction experiment with 10-fs X-ray free-electron laser (XFEL) pulses. We found that the structure of Xe nanoparticles is not pure face-centered cubic (fcc), the expected stable phase, but a mixture of fcc and randomly stacked hexagonal close-packed (rhcp) structures. Furthermore, we identified the instantaneous coexistence of the comparably sized fcc and rhcp domains in single Xe nanoparticles. The observations are explained by the scenario of structural aging, in which the nanoparticles initially crystallize in the highly stacking-disordered rhcp phase and the structure later forms the stable fcc phase. The results are reminiscent of analogous observations in hard-sphere systems, indicating the universal role of the stacking-disordered phase in nucleation.

Quantitative and Qualitative Analyses of Mass Spectra of OEL Materials by Artificial Neural Network and Interface Evaluation: Results from a VAMAS Interlaboratory Study.

Quantitative analysis of binary mixtures of tris(2-phenylpyridinato)iridium(III) (Ir(ppy)3) and tris(8-hydroxyquinolinato)aluminum (Alq3) by using an artificial neural network (ANN) system to mass spectra was attempted based on the results of a VAMAS (Versailles Project on Advanced Materials and Standards) interlaboratory study (TW2 A31) to evaluate matrix-effect correction and to investigate interface determination. Monolayers of binary mixtures having different Ir(ppy)3 ratios (0, 0.25, 0.50, 0.75, and 1.00), and the multilayers containing these mixtures and pure samples were measured using time-of-flight secondary ion mass spectrometry (ToF-SIMS) with different primary ion beams, OrbiSIMS (SIMS with both Orbitrap and ToF mass spectrometers), laser desorption ionization (LDI), desorption/ionization induced by neutral clusters (DINeC), and X-ray photoelectron spectroscopy (XPS). The mass spectra were analyzed using a simple ANN with one hidden layer. The Ir(ppy)3 ratios of the unknown samples and the interfaces of the multilayers were predicted using the simple ANN system, even though the mass spectra of binary mixtures exhibited matrix effects. The Ir(ppy)3 ratios at the interfaces indicated by the simple ANN were consistent with the XPS results and the ToF-SIMS depth profiles. The simple ANN system not only provided quantitative information on unknown samples, but also indicated important mass peaks related to each molecule in the samples without a priori information. The important mass peaks indicated by the simple ANN depended on the ionization process. The simple ANN results of the spectra sets obtained by a softer ionization method, such as LDI and DINeC, suggested large ions such as trimers. From the first step of the investigation to build an ANN model for evaluating mixture samples influenced by matrix effects, it was indicated that the simple ANN method is useful for obtaining candidate mass peaks for identification and for assuming mixture conditions that are helpful for further analysis.

Quantitative analysis of ToF-SIMS data of a two organic compound mixture using an autoencoder and simple artificial neural networks.

RATIONALE: Matrix effects cause a nonlinear relationship between ion intensities and concentrations in mass spectrometry, including time-of-flight secondary ion mass spectrometry (ToF-SIMS). Here, two artificial neural network (ANN)-based methods, autoencoder-based and simple ANN methods, were employed for the quantitative and qualitative analyses of a two organic compound mixture via ToF-SIMS. METHODS: The multilayer model sample contained a mixture of Irganox 1010 and Fmoc-pentafluoro-L-phenylalanine (Fmoc-PFLPA). The sample's positive and negative ion depth profiles were collected through ToF-SIMS. ToF-SIMS-derived cross-sectional image datasets were analyzed using three unsupervised methods, namely principal component analysis (PCA), multivariate curve resolution (MCR), and use of a sparse autoencoder (SAE). The supervised simple ANN method was optimized based on the spectra and validated by predicting the test dataset ratios of Irganox 1010. RESULTS: The results obtained using the SAE demonstrated linear calibration curves and appropriate material distribution images. The Irganox 1010 and Fmoc-PFLPA positive and negative ion datasets exhibited >0.97 correlation coefficients. The PCA and MCR results demonstrated lower linearity than that of SAE. Moreover, SAE weights indicated the ions important for each organic compound. The simple ANN method accurately predicted the ratios in the test dataset and indicated the important ions. CONCLUSIONS: Both the supervised and unsupervised methods based on ANN, which were employed in regulating nonlinear relationships, were effective in the quantitative and qualitative analyses of the ToF-SIMS data of the two organic compound mixtures. Regarding qualitative analysis, both ANN-based methods indicated specific ions from the molecules in the sample.

Sparse autoencoder-based feature extraction from TOF-SIMS image data of human skin structures.

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is a useful and versatile tool for surface analysis, enabling detailed compositional information to be obtained for the surfaces of diverse samples. Furthermore, in the case of two- or three-dimensional imaging, the measurement sensitivity in the higher molecular weight range can be improved by using a cluster ion source, thus further enriching the TOF-SIMS information. Therefore, appropriate analytical methods are required to interpret this TOF-SIMS data. This study explored the capabilities of a sparse autoencoder, a feature extraction method based on artificial neural networks, to process TOF-SIMS image data. The sparse autoencoder was applied to TOF-SIMS images of human skin keratinocytes to extract the distribution of endogenous intercellular lipids and externally penetrated drugs. The results were compared with those obtained using principal component analysis (PCA) and multivariate curve resolution (MCR), which are conventionally used for extracting features from TOF-SIMS data. This confirmed that the sparse autoencoder matches, and often betters, the feature extraction performance of conventional methods, while also offering greater flexibility.

Evaluation of Time-of-Flight Secondary Ion Mass Spectrometry Spectra of Peptides by Random Forest with Amino Acid Labels: Results from a Versailles Project on Advanced Materials and Standards Interlaboratory Study.

We report the results of a VAMAS (Versailles Project on Advanced Materials and Standards) interlaboratory study on the identification of peptide sample TOF-SIMS spectra by machine learning. More than 1000 time-of-flight secondary ion mass spectrometry (TOF-SIMS) spectra of six peptide model samples (one of them was a test sample) were collected using 27 TOF-SIMS instruments from 25 institutes of six countries, the U. S., the U. K., Germany, China, South Korea, and Japan. Because peptides have systematic and simple chemical structures, they were selected as model samples. The intensity of peaks in every TOF-SIMS spectrum was extracted using the same peak list and normalized to the total ion count. The spectra of the test peptide sample were predicted by Random Forest with 20 amino acid labels. The accuracy of the prediction for the test spectra was 0.88. Although the prediction of an unknown peptide was not perfect, it was shown that all of the amino acids in an unknown peptide can be determined by Random Forest prediction and the TOF-SIMS spectra. Moreover, the prediction of peptides, which are included in the training spectra, was almost perfect. Random Forest also suggests specific fragment ions from an amino acid residue Q, whose fragment ions detected by TOF-SIMS have not been reported, in the important features. This study indicated that the analysis using Random Forest, which enables translation of the mathematical relationships to chemical relationships, and the multi labels representing monomer chemical structures, is useful to predict the TOF-SIMS spectra of an unknown peptide.

Narrow-band Imaging Examination of Microvascular Architecture of Subcapsular Hepatic Tumors.

BACKGROUND: Intraoperative ultrasonography is the golden standard method for evaluation of liver tumors during hepatectomy. However, in laparoscopic surgery, accurate assessment of tumors may be difficult, particularly if the lesion is located nearby the liver surface because of the challenges in handling the intraoperative ultrasound and the lack of tactile sensation. In this study, we demonstrate the preliminary results of examining the microvascular architecture of subcapsular hepatic tumors using laparoscopic narrow-band imaging (NBI) to distinguish between malignant and benign tumors. MATERIALS AND METHODS: Thirty-five lesions were examined by NBI during laparoscopic hepatectomy for the presence of abnormal microvasculature on the liver surface in relation to hepatic tumors from January 2016 to August 2018. The microvascular findings were correlated with tumor localization and pathological diagnosis. RESULTS: The 35 examined nodules included 11 hepatocellular carcinoma, 18 colorectal liver metastasis, and six benign nodules. The mean tumor diameter was 26.3 (3-70) mm, and the distance from the liver surface to the tumor was 0.5 (0-5) mm. Microvessels on the liver surface were clearly visualized by NBI, consistent with malignant tumor localization. The tumors were thoroughly examined for the presence of three pathological microvascular features (enlargement, tortuosity, and heterogeneity). Abnormal microvascular patterns were found in 90.9% of hepatocellular carcinoma and 77.8% of colorectal liver metastasis, whereas neither normal sites nor benign lesions displayed microvascular abnormality. CONCLUSIONS: This study suggests that observing the microvessel image on the liver surface by NBI could be useful in tumor localization and differentiation between benign and malignant lesions.

Virtual reality with three-dimensional image guidance of individual patients' vessel anatomy in laparoscopic distal pancreatectomy.

PURPOSE: Three-dimensional virtual endoscopy (3DVE) has the potential advantage of enhanced anatomic delineation and spatial orientation during laparoscopic procedures. In the present study, we aimed to evaluate the impact of 3DVE guidance in laparoscopic distal pancreatectomy (LDP). METHODS: Thirty-eight patients presenting to our hospital with a variety of pancreatic tumors underwent preoperative computed tomography scanning to clearly define the major peripancreatic vasculature and correlate it with a 3DVE system (SYNAPSE VINCENT: Fujifilm Medical, Tokyo, Japan). This map served as the guide during preoperative planning, surgical education, and simulation and as intraoperative navigation reference for LDP. Operative records and pathological findings were analyzed for each procedure. Operative parameters were compared between the 38 patients in this study and 8 patients performed without 3DVE guidance at our institution. RESULTS: The 3DVE navigation system successfully created a preoperative resection map in all patients. Relevant peripancreatic vasculature displayed on the system was identified and compared during the intervention. The mean blood loss in LDP performed under 3DVE guidance versus LDP without 3DVE was 168.5 +/- 347.6 g versus 330.0 +/- 211.4 g, p = 0.008 while and the operative time was 171.9 +/- 51.7 min versus 240.6 +/- 24.8 min, p = 0.001. CONCLUSIONS: 3DVE in conjunction with a "laparoscopic eye" creates a preoperative and intraoperative three-dimensional data platform that potentially enhances the accuracy and safety of LDP.

Preventing clinically relevant pancreatic fistula with combination of linear stapling plus continuous suture of the stump in laparoscopic distal pancreatectomy.

BACKGROUND: Pancreatic fistula is one of the serious complications for patients undergoing distal pancreatectomy, which leads to significant morbidity. The aim of our study is to compare linear stapling closure plus continuous suture with linear stapling closure alone during laparoscopic distal pancreatectomy (LDP) in terms of clinically relevant postoperative pancreatic fistula (POPF) rate. METHODS: Twenty-two patients underwent LDP at our institution between 2011 and 2013. Twelve patients had linear stapling closure with peri-firing compression (LSC) alone compared with ten patients who had linear stapling closure, peri-firing compression plus continuous suture (LSC/CS) for stump closure of remnant pancreas in LDP. Biochemical leak and clinically relevant POPF were compared between both groups. RESULTS: POPF occurred in 4 of 12 (33.3%) patients with linear stapling closure while no patient developed a clinically relevant POPF in the triple combination of linear stapling, peri-firing compression plus continuous suture group (p = 0.043).1 patient (8.3%) in the LSC group and 5 patients (50%) in the LSC/CS group had evidence of a biochemical leak. There were no significant differences in operative time (188.3 vs 187.0 min) and blood loss (135 vs. 240 g) between both groups but there was a significantly of shorter length of hospital stay (11.9 vs. 19.9 days) in LSC/CS group (p = 0.037). There was no mortality in either group. CONCLUSIONS: The triple combination of linear stapling, peri-firing compression plus continuous suture in LDP has effectively prevented occurrence of clinically relevant ISGPF POPF. TRIAL REGISTRATION: The study was retrospectively registered September 30, 2019 at Showa University Ethics Committee as IRB protocol numbers 2943.

Individualized procedures for splenic artery dissection during laparoscopic distal pancreatectomy.

BACKGROUND: There are no established standard criteria for choosing the most appropriate procedure of splenic artery dissection during laparoscopic distal pancreatectomy (LDP). The aim of this study was to evaluate the clinical benefits of individualized procedures for splenic artery dissection during LDP based on the variations in arterial structure visualized on preoperative three-dimensional computed tomography (3D-CT). METHODS: Patients who underwent LDP following 3D-CT at a single center were retrospectively evaluated. 3D-CT images were used to construct virtual 3D laparoscopic images for surgical planning. The splenic artery was classified into two major anatomic types: type S that curves and runs suprapancreatic and type D that runs straight and dorsal to the pancreas. Splenic artery dissection was planned according to these two variations, with type S dissected using an suprapancreatic approach and type D using a dorsal approach. RESULTS: Type-specific dissection was applied for 30 patients: 25 (83%) with type S and 5 (17%) with type D splenic artery anatomies. In 25 (83%) patients, the splenic artery was successfully dissected using the planned surgical procedure, whereas the surgical plan had to be altered in 5 cases (17%) due to difficulty in dissecting the splenic artery. CONCLUSION: The individualized procedures for splenic artery dissection according to anatomic variations visualized on 3D-CT images can help improve the success and safety of LDP.

Ultrafast Structural Dynamics of Nanoparticles in Intense Laser Fields.

Femtosecond laser pulses have opened new frontiers for the study of ultrafast phase transitions and nonequilibrium states of matter. In this Letter, we report on structural dynamics in atomic clusters pumped with intense near-infrared (NIR) pulses into a nanoplasma state. Employing wide-angle scattering with intense femtosecond x-ray pulses from a free-electron laser source, we find that highly excited xenon nanoparticles retain their crystalline bulk structure and density in the inner core long after the driving NIR pulse. The observed emergence of structural disorder in the nanoplasma is consistent with a propagation from the surface to the inner core of the clusters.

Electron spectroscopic study of nanoplasma formation triggered by intense soft x-ray pulses.

Using electron spectroscopy, we investigated the nanoplasma formation process generated in xenon clusters by intense soft x-ray free electron laser (FEL) pulses. We found clear FEL intensity dependence of electron spectra. Multistep ionization and subsequent ionization frustration features are evident for the low FEL-intensity region, and the thermal electron emission emerges at the high FEL intensity. The present FEL intensity dependence of the electron spectra is well addressed by the frustration parameter introduced by Arbeiter and Fennel [New J. Phys. 13, 053022 (2011)].

Chemosynthetic homologues of Mycoplasma pneumoniae ß-glycolipid antigens for the diagnosis of mycoplasma infectious diseases.

Mycoplasma pneumoniae expresses ß-glycolipids (ß-GGLs) in cytoplasmic membranes, which possess a unique ß(1 → 6)-linked disaccharide epitope, which has high potential in biochemical and medicinal applications. In the present study, a series of ß-GGLs homologues with different acyl chains (C12, C14, C16, and C18) were prepared from a common precursor. An ELISA assay using an anti-(ß-GGLs) monoclonal antibody indicated that the synthetic homologues with long acyl chains had greater diagnostic potential in the order C18 > C16 > C14 > C12. Toward a simultaneous detection of natural glycolipids by mass spectrometry (MS), a deuterium-labeled C16 homologue (ß-GGL-C16-d3) was prepared and applied as an internal standard for a high-resolution electrospray ionization MS (ESI-MS) analysis. The ESI-MS analysis was used to identify and quantify acyl homologues (C16/C16, C16/C18, and C18/C18) of ß-GGL-C16 in cultured M. pneumoniae. A ß-GGLs homologue with a 1,2-diacetyl group (C2) was also prepared as a "water soluble" glycolipid homologue and characterized by 1H NMR spectroscopy. We envisage that each of these chemosynthetic homologues will provide promising approaches to solve medical and biological problems associated with mycoplasma infectious diseases (MIDs).

Determination of the surgical margin in laparoscopic liver resections using infrared indocyanine green fluorescence.

PURPOSE: Laparoscopic liver resection is increasingly used to treat patients with hepatic tumor. However, during laparoscopic resection, information obtained by palpation using laparoscopic forceps or from intraoperative ultrasonography is extremely limited, which may pose a risk for positive surgical margins. This study aimed to investigate the feasibility and clinical application of near-infrared (NIR) fluorescence imaging to guide laparoscopic liver resection of a liver tumor and secure the surgical margins. METHODS: A preliminary study in 25 patients was conducted. NIR imaging was used intraoperatively during laparoscopic liver resection. The liver tumors were preoperatively labeled by intravenously injecting the patients with indocyanine green dye (0.5 mg/kg), an NIR fluorescence agent. During the surgical procedure, the PINPOINT Endoscopic Fluorescence Imaging System was used to assess the surgical margin by using real-time endoscopic high-definition visible and NIR fluorescence imaging. RESULTS: All tumors were identified and resected laparoscopically by using the PINPOINT system, and all resections successfully secured the surgical margin. The pathological findings of all tumors indicated negative margins, defined as R0. CONCLUSIONS: This technique showed the potential to improve the intraoperative identification and demarcation of tumors. Its use could potentially reduce the number of positive resection margins.

[Present and Future of Navigation Surgery in Hepatobiliary and Pancreatic Surgery].

Hepatobiliary and pancreatic surgery is recognized as technically demanding due to the complicated local anatomy and diverse anatomical variation that require precise techniques. Therefore, preoperative simulation to understand the detailed local anatomy and intraoperative navigation methods for surgical guidance are needed. Intraoperative navigation for anatomical hepatectomy originated with dye injection into the dominant portal pedicle under intraoperative ultrasound guidance to identify hepatic segments, which was reported by Makuuchi et al in 1985. In recent years, with advancing medical technology, newer medical devices that promote the safety and reliability of various surgical procedures have been developed. In this article, we will discuss the current state and future prospects of intraoperative navigation in hepatobiliary and pancreatic surgery.

Routes for virtually guided endoscopic liver resection of subdiaphragmatic liver tumors.

PURPOSE: Laparoscopic and thoracoscopic/laparoscopic hepatectomy is a safe procedure that has potential advantages over open surgery. However, deeply positioned liver tumors require expert laparoscopic and thoracoscopic/laparoscopic hepatectomy techniques. Using simulated preoperative three-dimensional virtual endoscopy (P3DVE) guidance, we demonstrate herein that a thoracoscopic approach (TA), thoracoscopic-laparoscopic approach (TLA), and laparoscopic approach (LA) are all feasible and safe routes for performing pure laparoscopic and thoracoscopic/laparoscopic resection of liver tumors located in the 4a, 7, and 8 liver subdiaphragmatic areas. METHODS: Thirty-eight patients underwent laparoscopic and thoracoscopic/laparoscopic partial liver resection (TA 13 cases, TLA two cases, and LA 23 cases) of the subdiaphragmatic area at Showa University Hospital. All surgical approaches were preoperatively determined based on preoperative 3D virtual endoscopic simulation (P3DVES) visualization and findings using the image processing software SYNAPSE VINCENT(®). RESULTS: Laparoscopic and thoracoscopic/laparoscopic liver resection was successfully performed for all cases under P3DVE instruction. The mean operative times using TA, TLA, and LA approaches were 193, 185, and 190 min, respectively. Mean blood loss during TA, TLA, and LA was 179, 138, and 73 g, respectively. No patients required conversion to open surgery, and there were no deaths, although there were three cases of Clavien-Dindo grade I in TA along with three cases of grade I and one case of grade II in LA. CONCLUSIONS: TA, TLA, and LA routes performed under P3DVE instruction are feasible and safe to perform for pure laparoscopic and thoracoscopic/laparoscopic liver resection in selected patients with lesions located in the hepatic subdiaphragmatic area.

Study on the detection limits of a new argon gas cluster ion beam secondary ion mass spectrometry apparatus using lipid compound samples.

RATIONALE: Ar gas cluster ion beam secondary ion mass spectrometry (Ar-GCIB SIMS) has been developed as one of the most powerful tools used for analyzing complex biological materials because of its distinctively high secondary ion yield of large organic molecules. However, for the practical analysis of minor components in complex biological materials, the sensitivity of the technique is still insufficient. METHODS: The detection limits of our original Ar-GCIB SIMS apparatus were investigated by measuring lipid compound samples in positive ion mode. The samples were mixtures of 1,2-distearoyl-sn-glycero-3-phosphocholine (C44 H88 NO8 P, DSPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (C40 H80 NO8 P, DPPC). The primary ions were accelerated with 10 keV and the mean cluster size was 1500. The secondary [M+H](+) ions emitted from the sample were analyzed using an orthogonal acceleration time-of-flight mass spectrometer (oa-TOF-MS). In addition, the isotope abundance ratio and the ratio of the [M+H](+) ion signal to the fragment ion signal acquired with Ar-GCIB SIMS were compared with those obtained with conventional Bi cluster SIMS. RESULTS: Secondary [M+H](+) ions and some characteristic fragment ions were clearly observed with high quantitative accuracy in the mass spectra acquired with Ar-GCIB SIMS. The results were clearly better than those obtained with conventional Bi cluster SIMS. CONCLUSIONS: The detection limit of Ar-GCIB SIMS was found to be below 0.1% and was much lower than that of conventional Bi cluster SIMS because of the high [M+H](+) ion yield and the low background. The results suggested that the new Ar-GCIB SIMS apparatus has the capability to acquire valuable information on complex biological materials.

Existence of density inhomogeneity of liquid Te associated with liquid-liquid phase transition.

We performed small-angle x-ray scattering measurements of liquid Te using a synchrotron radiation facility and observed maximum scattering intensity near 620 K in the supercooled region (melting temperature 723 K). This indicates that density inhomogeneity exists in liquid Te, and the fact that this temperature coincides with the temperature at which the specific heat, sound velocity, and thermal expansion coefficient reach their maxima means that this density inhomogeneity is the cause of these thermodynamic anomalies. The thermodynamic anomalies in liquid Te had already been shown in the 1980s to be comprehensively explained by the inhomogeneity associated with the continuous liquid-liquid phase transition (LLT), but direct experimental evidence for the existence of the inhomogeneity had not been obtained. The present results, together with those already obtained for mixture systems (Te-Se, Te-Ge), indicate the existence of inhomogeneity associated with LLT in liquid Te systems, and strongly support the model. Recently, similar maximum scattering intensity has also been observed in supercooled liquid water, which exhibits thermodynamic anomalies similar to those of Te, indicating the universality of the inhomogeneous model or LLT scenario to explain the thermodynamics of such 'anomalous liquids'. Further development of the LLT scenario is expected in near future.

Primary retroperitoneal cavernous hemangioma: A case report and review of the literature.

Retroperitoneal cavernous hemangioma, a rare vascular tumor, has only 30 PubMed cases. Preoperative diagnostic criteria are unclear and often present asymptomatically until complications such as rupture or compression arise. We present a 73-year-old with chronic abdominal pain and a giant retroperitoneal tumor. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed an irregular space-occupying mass in the retroperitoneum, suggesting a retroperitoneal chronic expanding hematoma. Total surgical resection confirmed the diagnosis as retroperitoneal cavernous hemangioma.

Novel navigation for laparoscopic cholecystectomy fusing artificial intelligence and indocyanine green fluorescent imaging.

This preliminary study is the first to demonstrate that AI can precisely identify loose connective tissue during laparoscopic cholecystectomy and ICG fluorescent cholangiography. Tashiro and colleagues conclude that this novel real-time navigation modality fusing AI and ICG fluorescent imaging may enhance safety and provide more reliable laparoscopic or robotic surgery.

Color-coded laparoscopic liver resection using artificial intelligence: A preliminary study.

Tashiro and colleagues demonstrated for the first time that an artificial intelligence system can precisely identify intrahepatic vascular structures during laparoscopic liver resection in real time through color coding under bleeding and indocyanine green fluorescent imaging. The system supports real-time navigation and offers potentially safer laparoscopic or robotic liver surgery.