The human papillomavirus (HPV) vaccines have been widely introduced in immunization programs worldwide, however, it is not accepted in mainland China. We aimed to investigate the awareness and knowledge about HPV vaccines and explore the acceptability of vaccination among the Chinese population. A meta-analysis was conducted across two English (PubMed, EMBASE) and three Chinese (China National Knowledge Infrastructure, Wan Fang Database and VIP Database for Chinese Technical Periodicals) electronic databases in order to identify HPV vaccination studies conducted in mainland China. We conducted and reported the analysis in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Fifty-eight unique studies representing 19 provinces and municipalities in mainland China were assessed. The pooled awareness and knowledge rates about HPV vaccination were 15.95 % (95 % CI: 12.87–19.29, I
 2
  = 98.9 %) and 17.55 % (95 % CI: 12.38–24.88, I
 2
  = 99.8 %), respectively. The female population (17.39 %; 95 % CI: 13.06–22.20, I
 2 = 98.8 %) and mixed population (18.55 %; 95 % CI: 14.14–23.42, I
 2 = 98.8 %) exhibited higher HPV vaccine awareness than the male population (1.82 %; 95 % CI: 0.50–11.20, I
 2 = 98.5 %). Populations of mixed ethnicity had lower HPV vaccine awareness (9.61 %; 95 % CI: 5.95–14.03, I
 2 = 99.0 %) than the Han population (20.17 %; 95 % CI: 16.42–24.20, I
 2 = 98.3 %). Among different regions, the HPV vaccine awareness was higher in EDA (17.57 %; 95 % CI: 13.36–22.21, I
 2 = 98.0 %) and CLDA (17.78 %; 95 % CI: 12.18–24.19, I
 2 = 97.6 %) than in WUDA (1.80 %; 95 % CI: 0.02–6.33, I
 2 = 98.9 %). Furthermore, 67.25 % (95 % CI: 58.75–75.21, I
 2
  = 99.8 %) of participants were willing to be vaccinated, while this number was lower for their daughters (60.32 %; 95 % CI: 51.25–69.04, I
 2
  = 99.2 %). The general adult population (64.72 %; 95 % CI: 55.57–73.36, I
 2 = 99.2 %) was more willing to vaccinate their daughters than the parent population (33.78 %; 95 % CI: 26.26–41.74, I
 2 = 88.3 %). Safety (50.46 %; 95 % CI: 40.00–60.89, I
 2
  = 96.6 %) was the main concern about vaccination among the adult population whereas the safety and efficacy (68.19 %; 95 % CI: 53.13–81.52, I
 2
  = 98.6 %) were the main concerns for unwillingness to vaccinate their daughters. Low HPV vaccine awareness and knowledge was observed among the Chinese population. HPV vaccine awareness differed across sexes, ethnicities, and regions. Given the limited quality and number of studies included, further research with improved study designis necessary.

/pdf/awareness-and-knowledge-about-human-papillomavirus-2jxzjrp9if.pdf

Awareness and knowledge about human papillomavirus vaccination and its acceptance in China: a meta-analysis of 58 observational studies

/pdf/gmaw-dissimilar-welding-of-aisi-409-ferritic-stainless-steel-3c4xva2rik.pdf

GMAW dissimilar welding of AISI 409 ferritic stainless steel to AISI 316L austenitic stainless steel by using AISI 308 filler wire

The invention discloses a circulating water cooling liner device for welding. The liner device comprises a liner device body an a circulating water cooling device. The grooves of two to-be-welded plates are oppositely fixed on the upper side of the liner device body. The circulating water cooling device is connected with the liner device. A recessed longitudinal arc-shaped forming groove is formed in each of the four sides of a copper liner which is longitudinally positioned through a retaining plate. A water pump water outlet pipe is connected with a cooling water circulating hole of the copper pad and is connected with a water return pipe of a water storage tank through a water return hose. The invention further discloses an application method of the circulating water cooling liner device. The method includes: fixing a liner seat; selecting the width W1 of each longitudinal arc-shaped forming groove of the copper liner; tightly pressing the copper liner through the retaining plate; connecting water pipes at two ends of the copper liner; fixing the two to-be-welded plates; starting a water pump to feed water so as to cool the copper liner, and welding the two to-be-welded plates. By the longitudinal arc-shaped forming grooves in the copper liner, utilization rate of the copper liner is increased by three times, welding of plates of different thicknesses can be satisfied, and application cost is lowered.

Circulating water cooling liner device for welding and application method of liner device

The invention discloses a clamp structure for welding of a magnesium alloy sheet, and belongs to the technical field of tool clamps The clamp structure for the welding of the magnesium alloy sheet comprises a base, a cushion block and a pair of magnesium alloy sheet limiting mechanisms, wherein a cushion block embedding groove is formed in the upward side of the base in the use state, the cushion block is embedded in the cushion block embedding groove, a cavity is formed in the length direction and in the upward side of the cushion block in the use state, a set of vertical air vents are formed in the bottom of the cavity and in the length direction of the cavity, each vertical air vent is communicated with an air passage formed in the length direction of the cushion block, one end portion of the air passage is connected with one end of a back face protective gas lead-in pipe in a matched mode, the other end of the back face protective gas lead-in pipe is connected with a back face protective gas air source device, the other end portion of the air passage is sealed, one magnesium alloy sheet limiting mechanism is arranged at one side of the base in the length direction, and the other magnesium alloy sheet limiting mechanism is arranged at the other side of the base in the length direction The clamp structure for the welding of the magnesium alloy sheet guarantees welding quality, is compact in overall structure, and is convenient to operate

Clamp structure for welding of magnesium alloy sheet

The invention provides a device and a method for controlling welding deformation of thin plate butt-joint. The device comprises a welding platform, wherein liquid charge holes used for charging a cooling liquid are arranged in the welding platform and at positions below a butt-joint welding seam; and a compression device used for compressing thin plates is further arranged on the welding platform. The welding platform is made from copper. During welding, the two thin plates are compressed according to a butt-joint welding structure by the compression device, and the interiors of the liquid charge holes are charged with the cooling liquid; welding is completed, and the compression device is released after the thin plates are cooled; and the welding deformation of thin plate butt-joint is reduced through the abovementioned steps. With the adoption of the abovementioned structure and method, lots of heat generated during welding is brought by the cooling liquid, the thin plates are compressed by using the compression device above the thin plates cooperatively, and pressure springs on the compression device are capable of adjusting a compression force according to different plate thicknesses, so that the welding deformation of the thin plates can be quite effectively controlled.

Device and method for controlling welding deformation of thin plate butt-joint

Disclosed are a constraint radiating device for welding ferritic stainless steel plates and a welding method. The device is characterized in that a groove is formed in the middle of a base plate along the length or width direction of the base plate, a gas inlet channel which is parallel to the groove is formed below the groove, a radiating structure is inlaid in the groove, and a fixing structure for fixing ferritic stainless steel plates to be welded is further disposed on the base plate. The radiating structure is provided with a gas groove in the middle of a copper body along the length direction of the copper body, a plurality of gas holes which are communicated with the gas inlet channel are arranged at the bottom of the groove, and two water flowing holes are respectively disposed on the copper body and positioned on two sides of the gas groove. The method includes that the two ferritic stainless steel plates are placed on the base plate in a butt joint manner, and a butt joint line of the ferritic stainless steel plates corresponds to the gas groove on the base plate and is fixed; industrial pure argon is filled into the gas inlet channel on the base plate; circulating cooling water is fed into the water flowing holes; the two ferritic stainless steel plates are welded; and a formed weld joint is obtained. The constraint radiating device and the welding method have the advantages that a welded part is prevented from deforming, heat transfer speed is fast, and the back of the weld joint is attractively formed.

Constraint radiating device for welding ferritic stainless steel plates and welding method

Thin plates of 21% Cr ferritic stainless steel welded by pulsed gas tungsten arc welding at different pulse frequencies were investigated for the microstructure characteristics and hardness behavior. The welds contained columnar grains in the outer part and fine equiaxed grains in the central region due to the pulsed process.

Ruifeng Han

Papers

Constraint radiating device for welding ferritic stainless steel plates and welding method

Effect of pulse frequency on microstructure of 21% Cr ferritic stainless steel in pulsed gas tungsten arc welding