CMOS imager non-uniformity response correction-based high-accuracy spot target localization.

High-accuracy spot target detection based on a complementary metal-oxide semiconductor (CMOS) image sensor, such as astronomy magnitude, medicine, and astronomy photometrics, needs accurate pixel response. Because pixels have different silicon structures and read outputting, each pixel has non-uniformity response with specific illumination. The flat-field correction of a CMOS image sensor is crucial before image processing. In this work, a flat-field model and correction method based on spot scale areas of CMOS image sensor pixel response are proposed. Compared with traditional full-plane calibration, this method aims at spot areas to fit most selected normal pixels' mean response curve with different light intensities and exposure times, which can guarantee spot imaging areas with higher accurate pixel response. Finally, the accuracy of this flat-field correction method is evaluated by the influence on spot target extraction accuracy. The experimental results indicate that using this flat-field correction method can decrease the non-uniform variance from 7.34 (LSB/10 bit) to 1.91 (LSB/10 bit) (improved by 74.1%) and reduce the noise effect on spot extraction accuracy, which improves it from 0.3453 pixel to 0.0116 pixel (1σ). The proposed approach solves the problem of non-uniform pixel response and improves imaging SNR for high-accuracy spot target localization.

A 0.2 V Micro-Electromechanical Switch Enabled by a Phase Transition.

Micro-electromechanical (MEM) switches, with advantages such as quasi-zero leakage current, emerge as attractive candidates for overcoming the physical limits of complementary metal-oxide semiconductor (CMOS) devices. To practically integrate MEM switches into CMOS circuits, two major challenges must be addressed: sub 1 V operating voltage to match the voltage levels in current circuit systems and being able to deliver at least millions of operating cycles. However, existing sub 1 V mechanical switches are mostly subject to significant body bias and/or limited lifetimes, thus failing to meet both limitations simultaneously. Here 0.2 V MEM switching devices with ≳106 safe operating cycles in ambient air are reported, which achieve the lowest operating voltage in mechanical switches without body bias reported to date. The ultralow operating voltage is mainly enabled by the abrupt phase transition of nanolayered vanadium dioxide (VO2 ) slightly above room temperature. The phase-transition MEM switches open possibilities for sub 1 V hybrid integrated devices/circuits/systems, as well as ultralow power consumption sensors for Internet of Things applications.

Multiplexed living cells stained with quantum dot bioprobes for multiplexed detection of single-cell array.

The results of quantum dot (QD) probe preparation for multiplexed single-cell array staining and analysis are reported. By controlling the reaction temperature, time, and ratio of Cd to Se, multicolor CdSe QDs emitting fluorescence ranging from purple to red in a safer, simpler, and more convenient way than traditional methods is obtained. To detect cells using these oil-soluble QDs, they are first coated with water-soluble thioglycolic aid (TGA) so that biocompatible multiwavelength bioprobes can be obtained. QDs' surface is somewhat damaged when binding TGA to QDs is found, which results in a reduction of QDs' emission wavelength and a slight blue shift of QDs' emission wavelength after water-soluble modification with TGA. Comparison of the emission spectrum showed that it is negligible, and the fluorescent properties of QDs capped by TGA are still satisfactory. Living cells are then stained with multiplexed probes by conjugating TGA-QDs with antibodies specific to these cell antigens. Changes in fluorescence intensity can indicate change in the relative quantity of antigens expressed in the same cell caused by external stimulus, offering effective methods to multiplexed optical analysis of single cells.

[Effects of Chaiqin Chengqi Decoction on activation of nuclear factor-kappaB in pancreas of rats with acute necrotizing pancreatitis].

OBJECTIVE: To explore the mechanism of Chaiqin Chengqi Decoction (CQCQD) in treatment of rats with acute necrotizing pancreatitis (ANP). METHODS: Thirty SD rats were randomly divided into 3 groups: sham-operated (SO) group, ANP group and CQCQD-treated group. ANP was induced by retro-pumping 3.5% sodium cholate to common bile duct. Blood sample was collected from abdominal vein for examination and the pancreatic tissue samples were taken for making pathology section 6 hours later. The pancreatic tissue (HE staining) was observed by light microscope. The content of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) was detected with the method of enzyme-linked immunosorbent assay, and the activation of nuclear factor-kappaB (NF-kappaB) in pancreas was detected by immunohistochemical method. RESULTS: Compared with the SO group, there was dramatic increase in the white blood cell (WBC) counts and AMY level in the ANP group (P<0.05, P<0.01). Compared with the ANP group, the WBC counts and AMY level in CQCQD-treated group were significantly reduced (P<0.05). The edema, inflammatory infiltration, haemorrhage and necrosis scores and total pathological score in the ANP group were obviously higher than those in the SO group (P<0.01). The edema, haemorrhage and inflammatory infiltration scores and the total pathological score in CQCQD-treated group were decreased (P<0.05). The integral optical density of NF-kappaB p65 positive cells of pancreas in CQCQD-treated group was lower than that in the ANP group (P<0.05). CONCLUSION: CQCQD can reduce the content of serum TNF-alpha and IL-6, depress the activation of NF-kappaB, and lessen the pancreatic lesions.