Short-and long-term outcomes of one-stage versus two-stage gastrectomy for perforated gastric cancer: a multicenter retrospective propensity score-matched study.

OBJECTIVE: There is no scientific consensus about the treatment of perforated gastric cancer (PGC). Therefore, the aim of this study was to investigate which is the better treatment option for PGC between the single-stage and two-stage strategies. METHODS: All 81 PGC patients from 13 medical institutions were retrospectively enrolled in this study. The PGC patients who underwent R0 gastrectomy were divided into one-stage surgery and two-stage surgery groups. The clinicopathological characteristics of the two groups were compared, and 415 regular gastric cancer patients without perforation were randomly selected as a control. The propensity score matching (PSM) method was used to find matched regular GC patients with similar clinicopathological parameters. The OS (overall survival) and the number harvested lymph nodes from PGC patients and regular GC patients were compared. RESULTS: Compared with PGC patients who underwent one-stage surgery, those who underwent two-stage surgery harvested significantly more lymph nodes [31(27, 38) vs 17 (12, 24), P < 0.001], required less blood transfusion [0 (0, 100) vs 200 (0, 800), P = 0.034], had a shorter ICU stay [0 (0, 1.5) vs 3 (0, 3), P = 0.009], and had a significantly better OS (Median OS: 45 months vs 11 months, P = 0.007). Compared with propensity score-matched regular GC patients without perforation, PGC patients who underwent one-stage gastrectomy had a poorer quality of lymphadenectomy [17 (12, 24) vs 29 (21, 37), P < 0.001] and suffered a worse OS (Median OS: 18 months vs 30 months, P = 0.024). Conversely, two-stage gastrectomy can achieve a comparable quality of lymphadenectomy (P = 0.506) and a similar OS (P = 0.096) compared to propensity score-matched regular GC patients. CONCLUSIONS: For PGC patients in poor condition, two-stage treatment is a better option when D2 radical gastrectomy cannot be achieved in emergency surgery, based on our findings that two-stage gastrectomy could provide PGC patients with a better quality of lymphadenectomy and a better OS.

Combination of clinical information and radiomics models for the differentiation of acute simple appendicitis and non simple appendicitis on CT images.

To investigate the radiomics models for the differentiation of simple and non-simple acute appendicitis. This study retrospectively included 334 appendectomy cases (76 simple and 258 non-simple cases) for acute appendicitis. These cases were divided into training (n = 106) and test cohorts (n = 228). A radiomics model was developed using the radiomic features of the appendix area on CT images as the input variables. A CT model was developed using the clinical and CT features as the input variables. A combined model was developed by combining the radiomics model and clinical information. These models were tested, and their performance was evaluated by receiver operating characteristic curves and decision curve analysis (DCA). The variables independently associated with non-simple appendicitis in the combined model were body temperature, age, percentage of neutrophils and Rad-score. The AUC of the combined model was significantly higher than that of the CT model (P = 0.041). The AUC of the radiomics model was also higher than that of the CT model but did not reach a level of statistical significance (P = 0.053). DCA showed that all three models had a higher net benefit (NB) than the default strategies, and the combined model presented the highest NB. A nomogram of the combined model was developed as the graphical representation of the final model. It is feasible to use the combined information of clinical and CT radiomics models for the differentiation of simple and non-simple acute appendicitis.

Dependence of Creep Strain and Fatigue Behavior on Surface Characteristics of Resistive Strain Gauges.

Creep behavior and fatigue life are important performance indexes that affect the long-term stability of resistive strain gauges. The resistive strain gauges, fabricated with wet etching and resistance trimming, present micro-morphology such as textures and uneven edges on the surface and side-wall profile of sensitive grids. This paper observed the micro-morphology of the sensitive grids by microscope and analyzed its range of geometric dimensions. A sine function was used to establish equivalent geometric models for the surface textures and side-wall profile. Based on time hardening theory and the S-N curve, the dependence of micro-morphology of metal resistive strain gauges on creep behavior and fatigue life was studied. The results indicate that the roughness of micro-morphology has an influence on creep behavior and fatigue life. The surface textures and side-wall profile lead to the increase of creep strain and the decrease of fatigue life in varying degrees. When 60% of the ultimate stress of the strain gauges is loaded, the average creep strain in steady-state calculated by the maximum roughness of the side-wall profile reaches up to 6.95 times that of the perfect flat surface. Under the condition of loading 70% of the ultimate stress and the same roughness, the fatigue life led by side-wall profile could be reduced to 1/25 of the textured surface. The obtained achievements promote an understanding for optimizing the fabrication process of resistive strain gauges as well as developing high-precision and long-life force sensors.

Dependance of Gauge Factor on Micro-Morphology of Sensitive Grids in Resistive Strain Gauges.

The effect of micro-morphology of resistive strain gauges on gauge factor was investigated numerically and experimentally. Based on the observed dimensional parameters of various commercial resistive strain gauges, a modeling method had been proposed to reconstruct the rough sidewall on the sensitive grids. Both the amplitude and period of sidewall profiles are normalized by the sensitive grid width. The relative resistance change of the strain gauge model with varying sidewall profiles was calculated. The results indicate that the micro-morphology on the sidewall profile led to the deviation of the relative resistance change and the decrease in gauge factor. To verify these conclusions, two groups of the strain gauge samples with different qualities of sidewall profiles have been manufactured, and both their relative resistance changes and gauge factors were measured by a testing apparatus for strain gauge parameters. It turned out that the experimental results are also consistent with the simulations. Under the loading strain within 1000 µm/m, the average gauge factors of these two groups of samples are 2.126 and 2.106, respectively, the samples with rougher profiles have lower values in gauge factors. The reduction in the gauge factor decreases the sensitivity by 2.0%. Our work shows that the sidewall micro-morphology on sensitive grids plays a role in the change of the gauge factor. The observed phenomena help derive correction methods for strain gauge measurements and predict the measurement errors coming from the local and global reinforcement effects.

Development and Application of Resistance Strain Force Sensors.

Resistance strain force sensors have been applied to monitor the strains in various parts and structures for industrial use. Here, we review the working principles, structural forms, and fabrication processes for resistance strain gauges. In particular, we focus on recent developments in resistance stress transfer for resistance strain force sensors and the creep effect due to sustained loads and/or temperature variations. Various error compensation methods to reduce the creep effect are analyzed to develop a metrology standard for resistance strain force sensors. Additionally, the current status of carbon nanotubes (CNTs), silicon carbide (SiC), gallium nitride (GaN), and other wide band gap semiconductors for a wide range of strain sensors are reviewed. The technical requirements and key issues of resistance strain force sensors for future applications are presented.

Strain Transfer Characteristics of Resistance Strain-Type Transducer Using Elastic-Mechanical Shear Lag Theory.

The strain transfer characteristics of resistance strain gauge are theoretically investigated. A resistance strain-type transducer is modeled to be a four-layer and two-glue (FLTG) structure model, which comprises successively the surface of an elastomer sensitive element, a ground adhesive glue, a film substrate layer, an upper adhesive glue, a sensitive grids layer, and a polymer cover. The FLTG model is studied in elastic⁻mechanical shear lag theory, and the strain transfer progress in a resistance strain-type transducer is described. The strain transitional zone (STZ) is defined and the strain transfer ratio (STR) of the FLTG structure is formulated. The dependences of the STR and STZ on both the dimensional sizes of the adhesive glue and structural parameters are calculated. The results indicate that the width, thickness and shear modulus of the ground adhesive glue have a greater influence on the STZ ratio. To ensure that the resistance strain gauge has excellent strain transfer performance and low hysteresis, it is recommended that the paste thickness should be strictly controlled, and the STZ ratio should be less than 10%. Moreover, the STR strongly depends on the length and width of the sensitive grids.

Proteomics for cancer biomarker discovery.

The emergence of novel technologies allows researchers to facilitate the comprehensive analyses of genomes, transcriptomes, and proteomes in health and disease. The information that is expected from such technologies may soon exert a dramatic change in the pace of cancer research and impact dramatically on the care of cancer patients. These approaches have already demonstrated the power of molecular medicine in discriminating among disease subtypes that are not recognizable by traditional pathologic criteria and in identifying specific genetic events involved in cancer progression. This review covers a selection of advances in the realm of proteomics and its promise for cancer biomarker discovery. It also addresses issues regarding sample preparation and specificity and discusses current challenges that need to be overcome. Finally, the review touches on the efforts of the Early Detection Research Network at the National Cancer Institute in promoting biomarker discovery for translation at the clinical level.