Kimura's Method Research Articles

Robotic versus laparoscopic distal pancreatectomy on perioperative outcomes: a systematic review and meta-analysis

Robotic surgery has become a promising surgical method in minimally invasive pancreatic surgery due to its three-dimensional visualization, tremor filtration, motion scaling, and better ergonomics. Numerous studies have explored the benefits of RDP over LDP in terms of perioperative safety and feasibility, but no consensus has been achieved yet. This article aimed to evaluate the benefits and drawbacks of RDP and LDP for perioperative outcomes. By June 2022, all studies comparing RDP to LDP in the PubMed, the Embase, and the Cochrane Library database were systematically reviewed. According to the heterogeneity, fix or random-effects models were used for the meta-analysis of perioperative outcomes. Odds ratio (OR), weighted mean differences (WMD), and 95% confidence intervals (CI) were calculated. A sensitivity analysis was performed to explore potential sources of high heterogeneity and a trim and fill analysis was used to evaluate the impact of publication bias on the pooled results. Thirty-four studies met the inclusion criteria. RDP provides greater benefit than LDP for higher spleen preservation (OR 3.52 95% CI 2.62–4.73, p < 0.0001) and Kimura method (OR 1.93, 95% CI 1.42–2.62, p < 0.0001) in benign and low-grade malignant tumors. RDP is associated with lower conversion to laparotomy (OR 0.41, 95% CI 0.33–0.52, p < 0.00001), and shorter postoperative hospital stay (WMD − 0.57, 95% CI − 0.92 to − 0.21, p = 0.002), but it is more costly. In terms of postoperative complications, there was no difference between RDP and LDP except for 30-day mortality (RDP versus LDP, 0.1% versus 1.0%, p = 0.03). With the exception of its high cost, RDP appears to outperform LDP on perioperative outcomes and is technologically feasible and safe. High-quality prospective randomized controlled trials are advised for further confirmation as the quality of the evidence now is not high.

Spleen-preserving distal pancreatectomy with vein scarifying and artery saving as an alternative for Warshaw method

There are two main laparoscopic spleen-preserving distal pancreatectomy (LSPDP) methods. One is the Kimura method that preserves both spleen artery and vein, which has advantage in sustained splenic perfusion but has technical difficulties. Another is the Warshaw method which sacrificed splenic vessels and has significant risks of splenic infarction or gastric varix. Herein, we introduce a modification of LSPDP that preserves splenic arteries at the expense of the splenic vein. From 2010 to 2019, patients who planned for LSPDP due to tumors in the body or tail of the pancreas were enrolled. We first used the Kimura method (group K), than depending on the extent of splenic vessel sacrifice, we categorized them as either being eligible for Warshaw method (group W) modified Warshaw method (group MW) if we preserved splenic artery and sacrificed only splenic vein. After surgery, we took imaging study every 3 months and then every 6 or 12 months, to assess the presence of gastric varices or splenic infarction. Eighty-six patients were analyzed (group K, 50; group W, 15; and group MW, 21). The surgery took longer in group K than it did in either group W or group MW. The incidence of splenic infarction was lower in group MW than in group W (p = 0.035). The incidence of gastric varices or splenomegaly was no difference between group MW and group W. The MW method could serve as one of the LSPDP modalities that improve on the disadvantages of conventional LSPDP techniques.

A new manoeuvre of vascular control in laparoscopic spleen-preserving distal pancreatectomy: Retrospective review for a modified Kimura's method.

Background:The aim of this study is to explore a new manoeuvre of vascular control technique in laparoscopic spleen-preserving distal pancreatectomy (LSPDP).Materials and Methods:A total of 63 patients were diagnosed with pancreatic tumour in our hospital from January 2013 to December 2018. In these cases, Kimura technique was utilised in 33 patients and total blood flow blocked technique was used in 30 patients. The clinical data of these 63 patients of were retrospectively analysed.Results:Four groups of patients were operated smoothly. In Kimura group, 33 patients were carried out using Kimura technique. Four patients' spleens were resected because the spleen artery was damaged. Three patients among them were converted to open surgery. In the other group, one patient was converted to open and resected the spleen. When comparing the Kimura group with the last series group, the mean surgical time decreased by 27 min, the estimated blood loss decreased by 108 ml, which had a significant statistical difference, whereas postoperative haemorrhage and postoperative pancreatic fistula had no statistical difference.Conclusion:After ten patient's practice, application of new manoeuvre of vascular control technique in LSPDP is feasible and safe, with advantages of less blood loss and shorter operation time.

Accuracy and bias of methods used for root length measurements in functional root research

Summary Functional root traits are becoming a key measure in plant ecology, and root length measurements are needed for the calculation of root traits. Several methods are used to estimate the total root length (TRL) of washed root samples [e.g. modified line intersect (LI) method, WinRHIZOTM and IJ_Rhizo], but no standardized comparison of methods exists. We used a set of digital images of unstained root samples to compare measurements given by the LI method and automated methods provided by WinRHIZOTM and IJ_Rhizo. Linear regression models were used to detect bias. Both linear regression models and the Bland‐Altman`s method of differences were used to evaluate the accuracy of eight methods (1 manual, 2 semi‐automated and 5 automated) in comparison with a reference method that avoided root detection errors. Length measurements were highly correlated, but did not exactly agree with each other in 11 of 12 method comparisons. All tested methods tended to underestimate the TRL of unstained root samples. The accuracy of WinRHIZOTM was influenced by the thresholding method and the root length density (RLD) in the pictures. For the other methods, no linear relationship was found between accuracy and RLD. With WinRHIZOTM (global thresholding + pixel reclassification; RLD = 1 cm cm−2), the Regent's method and the Tennant's method underestimated the TRL by 7·0 ± 6·2% and 4·7 ± 7·9%, respectively. The LI method gave satisfactory results on average (underestimation: 4·2 ± 6·0%), but our results suggest that it can lead to inaccurate estimations for single images. In IJ_Rhizo, the Kimura method was the best and underestimated the TRL by 5·4 ± 6·1%. Our results showed that care must be taken when comparing measurements acquired with different methods because they can lead to different results. When acquiring root images, we advise to (i) increase the contrast between fine roots and background by staining the roots, and (ii) avoid overlapping roots by not exceeding a RLD of 1 cm cm−2. Under these conditions, good length estimates can be obtained with WinRHIZOTM (global thresholding + pixel reclassification). The Kimura method in IJ_Rhizo can be an alternative to WinRHIZOTM.

Опыт использования филогенетического анализа в эпидемиологическом расследовании случая заражения ВИЧ-инфекцией

Objective of the study was to investigate a criminal case of infection with HIV, applying molecular-genetic analysis of blood plasma samples from an estimated source of an infection and the recipient for evaluation of probability of epidemiological connection between them. Materials and methods. The study involved genotyping and phylogenetic analysis of nucleotide sequences of HIV-1 variants, isolated from patients in the investigated group and the control one (19 nucleotide sequences of the HIV-1 from the patients living in the Saratov region, and 15 nucleotide sequences from GenBank). Genotyping was performed using the commercial ViroSeq HIV-1 Genotyping System. The sub-typing of HIV-1 strains was carried out on-line, through the COMET HIV-1/2 and HCV and REGA HIV-1 Sybtyping Tool programs. Phylogenetic analysis of nucleotide sequences was carried out by Mega software, version 5.2. Phylogenetic trees were constructed; nucleotide distances were calculated by Kimura method (bootstrap level 1000). Results and conclusions. Virus variants, isolated from the studied samples, were defined as HIV-1 A subtype. Performed phylogenetic analysis showed that nucleotide sequences of the studied samples authentically grouped on the phylogenetic tree, forming a common cluster, which mismatched that of control group. Calculation of the genetic distance testifies that the genetic relation between the samples within the investigated group is higher, than between the same samples and those of the control group. Thus, by means of phylogenetic analysis it is shown that the strains received from an estimated source of infection and the recipient are genetically closer to each other, than to the strains from the group of comparison. In this regard, it is possible to claim with a big share of confidence that probability of epidemiological connection between them exists.

Stochastic Methods for PEMFC Parameter Identification

Fuel cells are complex multiphysical systems characterized by a stratified geometry consisting of thin layers of different materials. Their full characterization involves a number of physical parameters, which are important for quantifying and comparing the performance of the materials. The physical parameters are also used in fuel cell models, which allow the fast exploration of different operating scenarios and can be implemented in optimization procedures aimed at achieving the best structural and operating conditions. The system of equations involved in these models, e.g. the Nernst equation, the Butler-Volmer equation and the diffusion equation, are strongly non-linear; thus, the model itself is extremely sensitive to parameter variations. Careful ex-situ measurements of such parameters can be performed by means of a number of diagnostic techniques, whose results are however not completely consistent with fuel cell operation due to several effects, e.g. variable interactions and boundary effects in the thin layers of the fuel cell. Conversely, “in situ” measurements can provide meaningful operational values, but a very few techniques are available to determine a limited number of parameters.A solution can consist in multiple parameter identification from multiple fundamental measurements, such as polarization curve and electrochemical impedance spectroscopy, performed in different conditions, e.g. at different temperature, pressure, concentration, and humidification.If there is only one unknown parameter, the solution is easy, requiring just a statistical interpolating technique. In the case of multiple unknown parameters, which is the most frequent condition, the problem becomes increasingly difficult as the number of parameters increases as duplicity problem emerges, i.e., several groups of parameters may lead to the same performance (e.g. polarization curve).Recently, a number of numerical tools are under development to face this kind of problems, some based on stochastic mathematical models, each presenting specific features in terms of accuracy, convergence, stability, robustness, and calculation speed [1]. Among the most promising methods, some of which have already been applied to multiple fuel cell parameter identification, are the Ishibashi–Kimura method [2], the Lambert W-function method [3], the Levenberg-Marquardt algorithm (LMA), the Gauss-Newton algorithm (GNA), the hybrid artificial bee colony algorithm [4], the trust region method, the current switching method [5], the simulated annealing method [6], and the particle swarm optimization (PSO) [7], and the differential evolution method [8].The presentation will focus on the application of a particular class of stochastic optimization methods to the problem of multiple parameters identification. These methods have already been widely tested and applied successfully to the simultaneous search of sets of optimal parameters with different physical dimensions, making them ideal tools to cope with the present problem. Their recent relevant literature is vast. They are especially suited for multimodal and noisy functions over large search spaces, which makes them particularly appealing for the problem at hand. The main drawback of such methods is the high number of objective function evaluations needed for convergence; however, thanks to a particular formulation of the PEMFC model, such drawback can be of minor impact, i.e. the overall computational times are on the order of a few tens of seconds.We are going to present the application of two of the most well-known metaheuristic methods, namely Particle Swarm Optimization (PSO) and Differential Evolution (DE), developed in previous work and suitably adapted. It should be noted that PSO has already been applied to parameter identification for FCs, while the application of DE is novel in this context. This is somewhat surprising since, as results will show, DE provides better results and offers higher robustness. We will present the implementation details regarding PSO and DE. The optimization algorithms have not been tuned to the specific problem and algorithm control parameters have been chosen from reasonable values suggested in literature.

Spleen-preserving laparoscopic distal pancreatectomy: a report of 12 cases from a single institution

Objective To investigate the safety,feasibility,and operation skills of spleen- preserving laparoscopic distal pancreatectomy( SPLDP) in the treatment of tumors in the body and tail of the pancreas. Methods A retrospective analysis was performed on the medical records of 12 patients who underwent SPLDP at Fujian Provincial Hospital from October 2008 to December 2012; 11 cases had the spleen preserved by Kimura method,and the other one had the spleen preserved by Warshaw method. Results All patients successfully underwent SPLDP without conversion to laparotomy. The mean operative time was 172. 5 min( 120- 240 min); the mean intraoperative blood loss was 191. 7 ml( 50- 400 ml); the mean postoperative length of hospital stay was 9. 5 days( 4- 25 days). Three patients had grade B pancreatic fistula after operation and were cured after adequate drainage. After operation,solid pseudopapillary tumor of the pancreas was pathologically confirmed in 4 cases,pancreatic neuroendocrine carcinoma in 2 cases,pancreatic islet cell tumor in 2 cases,pancreatic pseudocyst in 2 cases,and pancreatic cystadenoma in 2 cases. The duration of postoperative follow- up was 6- 51 months,and no diabetes and tumor recurrence were detected. Conclusion SPLDP is safe and feasible in the treatment of benign and low- grade malignant tumors in the body and tail of the pancreas.

Evaluation of methods to extract parameters from current–voltage characteristics of solar cells

An evaluation of methods is represented to extract parameters from the current–voltage (I–V) characteristics of solar cells. This evaluation includes five aspects: applicability, convergence, stability, calculation speed, and error on various types of I–V data. Six current popular extraction methods are discussed and evaluated in this work. We find that the widely adopted method using the reciprocals of slope at two points is the fastest and simplest approach to estimating resistances, but it is an incomplete method to obtain the other parameters. Of the five complete methods, the Ishibashi–Kimura method shows the best accuracy (4.5% average error) while having bad applicability. Generally speaking, the Lambert W-function method is the best comprehensive method with good accuracy, applicability, and convergence, though the calculation speed is relatively lower than the other four methods.

Correlation between Preoperative Kimura Inching Studies and Intraoperative Findings during Endoscopic-Assisted Decompression of the Ulnar Nerve at the Elbow

During the evolution of the senior author's technique of ulnar nerve transposition to in situ decompression for ulnar neuropathy at the elbow, nerve conduction studies (NCS) including the Kimura inching method were performed preoperatively in an effort to ensure that all potential sites of compression were investigated intraoperatively. The purpose of this study is to compare the results of the Kimura inching technique with the intraoperative findings noted during decompression of the ulnar nerve at the elbow. The medical records of consecutive patients who underwent in situ decompression of their ulnar nerves combined with endoscopic examination between March and December of 2009 were retrospectively reviewed. The site of ulnar nerve compression noted using the Kimura inching technique was compared with the intraoperative findings. Twelve consecutive patients (four with bilateral symptoms) underwent endoscopic ulnar nerve compression in the study period for a total of 16 cases analyzed. In 12 cases, the Kimura method localized the site of compression to Osborne's bands and/or the aponeurosis of the flexor carpi ulnaris (FCU). Intraoperatively, compression was noted at Osborne's bands, the FCU aponeurosis, and/or the FCU) muscle proper in all 16 patients. There was partial or full correlation between the nerve conduction data and intraoperative findings in 13/16 cases. There was good but not perfect agreement between the NCS and intraoperative findings, perhaps because transcutaneous NCS are less accurate when a nerve is surrounded by muscle. The information obtained in this study is valuable when planning surgery to address ulnar nerve compression.

Estimation of Incident and Reflected Waves Using Simulated Annealing

A new time-domain method for separating incident and reflected waves in wave flumes using any number of wave gauges is presented. The method (named LASA) is based on a local approximation model considering linear and Stokes II nonlinear components, and a simulated annealing algorithm to calculate the parameters of the local approximation model. The LASA method is directly applicable to experiments in wave flumes with an arbitrary number of wave gauges, but the LASA concept may be extended to laboratory and field three-dimensional experiments by selecting the appropriate local approximation model. The LASA method has been compared to the two-point and Kimura's method and has proved to be very robust. The application of the LASA method to physical experiments using nonstationary regular and random waves generated estimations of incident and reflected waves with relative mean squared errors lower than 3% for regular waves and ranging from 4 to 16% depending on the spectral shape.

Variance and Covariance of the Number of Amino Acid Substitutions Estimated by Kimura's Method.

Since the process of amino acid substitution is stochastic, it is of great importance to consider the variance and covariance of the number of amino acid substitutions. Formulae for the variance and covariance of the number of amino acid substitutions estimated by Kimura's method are presented. The bootstrap method shows that the formulae are accurate. The formulae are useful for studies of molecular evolution, e.g., reconstruction of a minimum-evolution tree and the relative-rate test.

Wide distribution of two subtypes of HIV-1 in Thailand.

Scientists wanted to identify the genetic characteristics of 2 HIV-1 subtypes in Thailand. Staff from regional laboratories of the Ministry of Public Health took blood samples from people in various high risk groups and from all regions of the country. Staff at the National Institutes of Health in Bangkok then did lymphocyte separation, DNA extraction, and virus culture. They took the extracted DNA specimens and sent them to the US Centers for Disease Control where scientists did serologic testing, polymerase chain reaction, and sequence determination. They used Kimura's method to study sequence variations. They sequenced 300 nucleotides, including the C2-V3 domains of HIV-1 envelope gene and/or hybridization. Every risk group had HIV-1 subtype A, but subtype B was mostly found in drug users. Subtype A had spread mainly among heterosexuals. The mean intraperson variation for subtypes A and B stood at 2% and 2.7%, respectively, while the interperson variation within subtype A and B stood at 3.8% and 3.7%, respectively. The mean interperson variation between subtypes A and B from different persons was 18.1%. Phylogenetic tree analysis showed that subtype B identified with about 85% of the sequence as that of the North American isolates, making it more closely related to them than to African isolates (about 75% sequence identity). On the other hand, subtype A had a GPGQ motif at the V3 crown which was common among African HIV-1 isolates. Antibodies which usually recognize HIV-1 MN strains (which have the GPGR motif) may not react wholly with the V3 loop from the Thailand subtype A viruses, thus the GPGQ motif at the V3 crown may pose a problem. Now for the first time, scientists can follow the natural history of 2 HIV-1 subtypes and determine their relative pathogenicity and transmission efficiency between adults or from mother to infant. The relative homogeneity of the HIV-1 strains in Thailand presents a theoretical advantage in designing vaccines for potential large-scale clinical trials.

一側性内リンパ水腫モルモットの台形方式回転検査成績に関する研究

Obliteration of the right endolymphatic sac was performed by Kimura's method in 57 guinea pigs with normal hearing and vestibular function. However, 43 animals exhibited postoperative cerebellopontile disturbance and labyrinthitis detected by gait test, ABR test and histological examination. The remaining 14 guinea pigs were evaluated periodically by the trapezoid rotation test. Two weeks after the operation, 11 of these 14 guinea pigs exhibited prolonged right beating nystagmus based on the labyrinthine preponderance of impaired side (Lpi). In addition, endolymphatic hydrops was histological detected in the labyrinth on the operation side. A positive relation was observed between the degree of endolymphatic hydrops and the degree of Lpi. Lpi at 4 weeks after the operation was markedly lower than that at 2 weeks (P = 0.05). Therefore, the degree of Lpi was thought to be influenced by the rate of hydrops development. These results corresponded with the clinical findings that the degree of Lpi increases prior to vertiginous episodes in Meniere's patients.

A Monte Carlo study of a system of close-packed interacting dimers

A new Monte Carlo algorithm for generation of samples of close-packed dimer configurations distributed according to the Gibbs canonical ensemble for some interaction Hamiltonian is suggested. The local change of configuration is achieved by rotation of a randomly chosen pair of nearest neighbor parallel dimers. A proof is given that in the case of a square lattice with edges the Markov chain of dimer configurations generated by any random sequence of such rotations is irreducible provided that each pair is rotated with nonvanishing probability. A simple model of interacting dimers is considered in which the interaction energy of a configuration is proportional to the total number of pairs of nearest neighbor parallel dimers in that configuration. The partition function of the system is estimated by using the Sogo and Kimura method of distribution functions. The free energy, internal energy, entropy and specific heat are estimated for lattices of size 8 × 8, 10 × 10 and 14 × 14, in a wide range of reduced temperatures. It is found that the specific heat exhibits a pronounced peak which becomes narrower and higher with the increase of the lattice size, simultaneously shifting to the higher temperatures.