In order to improve the noise ratio and stability of the amplified small-signal in microwave-induced thermoacoustic tomography,an amplifying circuit with wide band and high voltage gain is designed in this paper.The results show that the voltage gain is up to 80dB and the bandwidth is about 7MHz.

Objective To build finite-element models of cerebral hemorrhage on which a simulation study of electrical impedance tomography(EIT) is based.Method With a kind of four-layer concentric circle model of head,finite-element method and dynamic NOSER algorithm are performed to reconstruct the images.Result As to the single-focus model of the cerebral hemorrhage,the focus can be clearly imaged,while to the several-focus model,the focuses can be imaged with vaguely adjacent boundaries.Conclusion The dynamic NOSER algorithm is an effective method to image cerebral hemorrhage in EIT.

It is a technological difficulty to acquire data from ultrasound with ultra-band in the study of microwave-induced thermoacoustic tomography. A high-speed data acquisition system for the ultrasonic signal with a frequency fewer than 500 MHz is designed in the paper. The result obtained demonstrates that the system holds good for microwave-induced thermoacoustic tomography.

Objective To explore the clinical significance of expressing multiple autoantibodies in patients with autoimmune encephalitis.Methods Cerebrospinal fluid and serum were tested in patients with undefined encephalitis admitted to Peking Union Medical College Hospital from May 2013 to December 2014.Indirect immunofluorescence test was firstly used to identify the antibodies to neuronal cell-surface or synaptic receptors (including N-methyl-D-aspartate receptor (NMDAR),contactin-associated protein-like 2 (CASPR2),α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR),leucine-rich glioma inactivated protein 1 (LGI1),and gamma-aminobutyric acid beta receptor (GABABR)).In those patients with positive antibodies,antibodies against intracellular neuronal antigens associated with paraneoplastic neurological symptoms were tested.Anti-aquaporin protein-4 (AQP4) antibody was tested depending on patients' clinical manifestations.Results Ten patients were detected combined with additional autoantibodies in 531 patients with positive antibodies related to autoimmune encephalitis.AntiHu antibody was positive in 5 patients with anti-GABABR encephalitis,in 1 of whom anti-NMDAR antibody was also identified;anti-AQP4 antibody was positive in 1 patient with relapsing anti-NMDAR encephalitis;anti-CASPR2 and anti-Yo antibodies were respectively positive in 2 patients with anti-LGI1 encephalitis;anti-CV2 and anti-Hu antibodies were respectively positive in 2 patients with anti-AMPAR encephalitis.Clinical presentation of all cases was consistent with typical encephalitis or limbic encephalitis.Brain stem was involved in 3 patients.Peripheral sensory neuropathy was present in 1 patient,while myalgia and fasciculation were present in 1 patient.Seven patients responded well to the immunotherapy.Tumors were pathologically or radiologically confirmed in 7 cases,including lung cancer in 5 cases,suspected thymoma in 1 case and highly suspected mediastinal tumor without pathological identification in 1 case.Conclusions Due to the pathological mechanism,co-existence of multiple autoantibodies affects clinical manifestations of patients and results in variation and overlap of them.The additional positivity of onconeuronal antibodies directs the search for occult tumor.

According to the results of analyzing the microwave-induced thermoacoustic signals, the amplitude and frequency were estimated and the designing parameters of preprocessor were decided. Based on the parameters, the signals preprocessor was designed with the band pass frequency ranging from 50 KHz to 3MHz, the gain ranging from 55 dB to 105 dB and the output noise being 1.32 V when the input was zero and the gain was 105 dB. The de-noising method of thermoacoustic signals was also discussed. The signals can be picked up by the preprocessor combined with the digital multipoint average method. The amplitude of signals is only 5 microV or even less. The results indicated that the preprocessor can meet the needs of thermoacoustic signals acquisition in bandwidth, gain and noise control.
Acoustics ; instrumentation ; Algorithms ; Biophysical Phenomena ; Computer-Aided Design ; Equipment Design ; Microwaves ; Thermography ; instrumentation ; methods ; Tomography ; instrumentation ; methods

Objective:To analyze the clinical characteristics of patients undergoing extracorporeal cardiopulmonary resuscitation (ECPR), and to explore the risk factors leading to poor prognosis.Methods:The clinical data of 95 patients with ECPR admitted to the First Affiliated Hospital of Zhengzhou University from January 2020 to May 2023 were retrospectively analyzed. According to the survival status at the time of discharge, the patients were divided into the survival group and death group. The difference of clinical data between the two groups was compared to explore the risk factors related to death and poor prognosis. Risk factors associated with death were identified by Binary Logistic regression analysis. Results:A total of 95 patients with ECPR were included in this study, 62 (65.3%) died and 33 (34.7%) survived at discharge. Patients in the death group had longer low blood flow time [40 (30, 52.5) min vs. 30 (24.5, 40) min ] and total cardiac arrest time[40 (30, 52.5) min vs. 30(24.5, 40) min], shorter total hospital stay [3 (2, 7.25) d vs. 19 (13.5, 31) d] and extracorporeal membrane oxygenation (ECMO) assisted time [26.5 (17, 50) h vs. 62 (44, 80.5) h], and more IHCA patients (56.5% vs. 33.3%) and less had spontaneous rhythm recovery before ECMO (37.1% vs. 84.8%). Initial lactate value [(14.008 ± 5.188) mmol/L vs.(11.23 ± 4.718) mmol/L], APACHEⅡ score [(30.10 ± 7.45) vs. (25.88 ± 7.68)] and SOFA score [12 (10.75, 16) vs. 10 (9.5, 13)] were higher ( P< 0.05). Conclusions:No spontaneous rhythm recovery before ECMO, high initial lactic acid and high SOFA score are independent risk factors for poor prognosis in ECPR patients.

With the rapid economic development and dramatic changes in lifestyle, the prevalence of overweight and obesity in China has been increasing significantly and become a serious public health threat. This article introduced the main contents of "China Blue Paper on Obesity Prevention and Control", aiming to facilitate understanding and applications of the "China Blue Paper on Obesity Prevention and Control" by policymakers, researchers and practitioners in related fields. Built upon these, recommendations were made for obesity screening, diagnosis, treatment and management, prevention and control policies and strategies, and future research priorities in China.