Biocompatible Material-Based Flexible Biosensors: From Materials Design to Wearable/Implantable Devices and Integrated Sensing Systems.

Human beings have a greater need to pursue life and manage personal or family health in the context of the rapid growth of artificial intelligence, big data, the Internet of Things, and 5G/6G technologies. The application of micro biosensing devices is crucial in connecting technology and personalized medicine. Here, the progress and current status from biocompatible inorganic materials to organic materials and composites are reviewed and the material-to-device processing is described. Next, the operating principles of pressure, chemical, optical, and temperature sensors are dissected and the application of these flexible biosensors in wearable/implantable devices is discussed. Different biosensing systems acting in vivo and in vitro, including signal communication and energy supply are then illustrated. The potential of in-sensor computing for applications in sensing systems is also discussed. Finally, some essential needs for commercial translation are highlighted and future opportunities for flexible biosensors are considered.

Development of an innovative nomogram of risk factors to predict postoperative recurrence of gastrointestinal stromal tumors.

BACKGROUND: There are many staging systems for gastrointestinal stromal tumors (GISTs), and the risk indicators selected are also different; thus, it is not possible to quantify the risk of recurrence among individual patients. AIM: To develop and internally validate a model to identify the risk factors for GIST recurrence after surgery. METHODS: The least absolute shrinkage and selection operator (LASSO) regression model was performed to identify the optimum clinical features for the GIST recurrence risk model. Multivariable logistic regression analysis was used to develop a prediction model that incorporated the possible factors selected by the LASSO regression model. The index of concordance (C-index), calibration curve, receiver operating characteristic curve (ROC), and decision curve analysis were used to assess the discrimination, calibration, and clinical usefulness of the predictive model. Internal validation of the clinical predictive capability was also evaluated by bootstrapping validation. RESULTS: The nomogram included tumor site, lesion size, mitotic rate/50 high power fields, Ki-67 index, intracranial necrosis, and age as predictors. The model presented perfect discrimination with a reliable C-index of 0.836 (95%CI: 0.712-0.960), and a high C-index value of 0.714 was also confirmed by interval validation. The area under the curve value of this prediction nomogram was 0.704, and the ROC result indicated good predictive value. Decision curve analysis showed that the predicting recurrence nomogram was clinically feasible when the recurrence rate exceeded 5% after surgery. CONCLUSION: This recurrence nomogram combines tumor site, lesion size, mitotic rate, Ki-67 index, intracranial necrosis, and age and can easily predict patient prognosis.

Inorganic Perovskite Quantum Dot-Based Strain Sensors for Data Storage and In-Sensor Computing.

Although remarkable improvement has been achieved in stretchable strain sensors, challenges still exist in aspects including intelligent sensing, simultaneous data processing, and scalable fabrication techniques. In this work, a strain-sensitive device is presented by fabricating a CsPbBr3 quantum dots (QDs) floating-gate field-effect transistor (FET) sensing array on thin polyimide (PI) films. The FET exhibits an excellent on/off ratio (>103) and a large memory window (>2 V). With the introduction of CsPbBr3 QDs as the trapping layer, an additional UV response is obtained because of the photogenerated charge carriers that significantly enhance the source-drain current (IDS) of the device. At each electrical state, the IDS varies with the strains and the sensing range is from compressive +12.5% to tensile -10.8%. Excellent data retainability and mechanical durability demonstrate the high quality and reliability of the fabricated sensors. Furthermore, synapse functions including long-term potentiation (LTP), long-term depression (LTD), etc., are emulated at the device level. Linearity factor changes of LTP/LTD in different sensing scenarios demonstrate the reliability of the device and further confirm the different sensing mechanisms with/without UV illumination. Our results exhibit the potential of transistor-based devices for multifunctional intelligent sensing.

Stacked Two-Dimensional MXene Composites for an Energy-Efficient Memory and Digital Comparator.

Two-dimensional MXene has enormous potential for application in industry and academia owing to its surface hydrophilicity and excellent electrochemical properties. However, the application of MXene in optoelectronic memory and logical computing is still facing challenges. In this study, an optoelectronic resistive random access memory (RRAM) based on silver nanoparticles (Ag NPs)@MXene-TiO2 nanosheets (AMT) was prepared through a low-cost and facile hydrothermal oxidation process. The fabricated device exhibited a typical bipolar switching behavior and controllable SET voltage. Furthermore, we successfully demonstrated a 4-bit in-memory digital comparator with AMT RRAMs, which can replace five logic gates in a traditional approach. The AMT-based digital comparator may open the door for future integrated functions and applications in optoelectronic data storage and simplify the complex logic operations.

[Evaluation of insulin secretion and insulin resistance by hyperglycemic clamp in Graves disease patients with impaired glucose tolerance].

OBJECTIVE: To investigate the state of insulin secretion and insulin resistance in patients of Graves disease (GD) with impaired glucose tolerance (IGT) by hyperglycemic clamp. METHODS: Six cases of Graves disease with IGT were selected as GD + IGT group and ten healthy volunteers as normal control group (NC group). All the subjects were required to fast for 12 hours and then underwent hyperglycemic clamp to assay insulin secretion and insulin sensitivity. Glutamic acid decarboxylase antibody (GAD-A) was tested in all the subjects. RESULTS: Insulin secretion in GD + IGT group was significantly higher than that in NC group. The 1st phase insulin secretion (1PH) was (636.31 +/- 105.54) mIU/L vs (233.56 +/- 21.33) mIU/L, P = 0.001. The 2nd phase insulin secretion (2PH) was (146.68 +/- 25.00) mIU/L vs (67.06 +/- 6.23) mIU/L, P = 0.03. The maximal insulin secretion during 120 - 150 minutes (Ins(120 - 150)) was (195.05 +/- 32.94) mIU/L vs (87.64 +/- 9.78) mIU/L, P = 0.04. The hyperglycemic clamp insulin sensitivity index (average glucose metabolic rate during 120 - 150 minutes/Ins(120 - 150)) was significantly lower in GD + IGT group than that in NC group (11.52 +/- 1.90 vs 21.72 +/- 3.25, P = 0.04). GAD-A was negative in all subjects. CONCLUSION: Cases of GD with IGT show significant insulin resistance with compensated elevated insulin secretion.

[Evaluation of first phase insulin secretion by a nateglinide-intravenous glucose insulin release test in newly diagnosed type 2 diabetics].

OBJECTIVE: To evaluate the function of the first phase of insulin secretion of pancreatic B cells in newly diagnosed type 2 diabetics using nateglinide-intravenous glucose insulin release test (NG-IVGIRT). METHODS: NG-IVGIRT and intravenous glucose insulin release test (IVGIRT) were done in 8 patients with newly diagnosed type 2 diabetes mellitus and NG-IVGIRT was done in 8 normal people. Insulin and glucose of blood were determined at - 15, 0, 2, 4, 6, 8 and 10 min in NG-IVGIRT or IVGIRT. RESULTS: The response of 0 - 10 min insulin to NG-IVGIRT was significantly higher than that to IVGIRT in the diabetics. The response of insulin to NG-IVGIRT in the normal controls was much higher than that in the diabetics. The area under curve (AUC) of insulin to NG-IVGIRT was apparently elevated and the AUC of glucose to NG-IVGIRT reduced in the normal controls as compared with those in the diabetics. CONCLUSION: The results indicated that the reserve of first phase insulin secretion in newly diagnosed type 2 diabetics could be provoked in some degree by NG-IVGIRT and there was a big difference in the reserve of the first phase of insulin secretion provoked by NG-IVGIRT between newly diagnosed type 2 diabetics and normal people.

[DNA repair of CHL cells and HeLa cells after DNA damage induced by different oxidative agents].

OBJECTIVE: To investigate DNA repair in CHL cells and HeLa cells after DNA damage induced by different oxidative agents. METHODS: CHL cells and HeLa cells were exposed to various damaging agents, CHL cells: H(2)O(2) for 25 min, K(2)Cr(2)O(7) for 105 min, doxorubicin (Dox) for 75 min HeLa cells: H(2)O(2) for 25 min, K(2)Cr(2)O(7) for 105 min; then cells were continuously cultured for 0-3 h after washing. Alkaline single cell gel electrophoresis (ASCGE) assay was used to detect DNA strand breaks. RESULT: (1) DNA strand breaks were induced in CHL cells after exposure to H(2)O(2) K(2)Cr(2)O(7) or Dox, which were repaired evidently after continuous culture for 1 h(P<0.01). The damages induced by H(2)O(2) or K(2)Cr(2)O(7) were repaired completely after culture for 2-3 h. However, the demage induced by Dox was repaired incompletely. (2) DNA strand breaks were induced also in HeLa cells after exposure to H(2)O(2) or K(2)Cr(2)O(7), which were repaired evidently after continuous culture for 0.5 h(P<0.01),and completely after culture for 1 h. (3) The regression coefficient related to the rate of comet cells and repair time was statistically different (P<0.05) between CHL cells and HeLa cells. CONCLUSION: DNA damage induced by Dox is repaired more difficult than that induced by H(2)O(2) or K(2)Cr(2)O(7). The repair initiates immediately after DNA damage in both of cells, but more rapidly in HeLa cells than in CHL cells.