Adielectrophoresis-basedmicrofluidicchipappliedtocellspatterningisdesignedandfabricated, and it demonstrates non-contact and batch manipulation of cells. The microfluidic chip employs a PDMS microchannel and two ITO electrodes, which are designed as astep shape. The distribution of electric field caused by the microelectrodes is simulated by finite element simulation software, COMSOL. The position of the maximum intensity of electric field is also determined. The ITO microelectrodes and the PDMS microchannel are fabricated using MEMS fabrication process. After oxygen plasma surface treatment, the PDMS microchannel and glass substrate with the ITO microelectrodes are aligned and bonded to form experimental microfluidic chip. Through DEP experiment with the varying frequencies, DEP response of yeast cells is examined, and the electric field frequency of the both positive and negative DEP responses are confirmed. The results showed that yeast cells in solution conductivity of 60 μS/cm had negative DEP movement at the frequency of 1 kHz to 10 kHz, positive DEP movement at the 500 kHz to 10 MHz, and no DEP movement at the 50 kHz. Under the condition of the sinusoidal potential of 8Vp-p and the electric field frequency of 5 MHz, the yeast cells were aligned into chains along the step edge of microelectrodes.

Malnutrition and dehydration are prevalent in the elderly poplulation, and obesity is also a growing problem, which pose a serious challenge to the nutritional management in geriatrics. In order to better guide clinical practice, the European Society for Clinical Nutrition and Metabolism (ESPEN) published the practical guideline on clinical nutrition and hydration in geria-trics on March 5, 2022. This guideline provides 82 recommendations on clinical nutrition and hydration in geriatrics based on clinical practicability, covering basic problems and general prin-ciples, prevention and treatment of malnutrition/nutri-tional risk, prevention and treatment of specific diseases, as well as prevention and treatment of obesity, along with flow-charts, hoping to be convenient for doctors, nutritionists and nurses to use in clinical practice.