Objective: To investigate the influencing factors for cognitive function among aluminum workers, so as to provide the basis for intervention and prevention of cognitive function among aluminum-exposed populations. Methods: From July to August 2019, male aluminum workers in the electrolytic aluminum workshop of an aluminum factory in Shanxi Province were selected using the cluster sampling method. Demographic information, prevalence of chronic diseases, lifestyle behaviors, night shifts, and sleep quality were collected through questionnaire surveys. Blood aluminum levels were measured using inductively coupled plasma-mass spectrometry. Cognitive function was investigated using the Montreal Cognitive Assessment. Factors affecting cognitive function among aluminum workers were analyzed by a quantile regression model. Results: A total of 142 aluminum workers were surveyed, including 57 workers aged 20 to <40 years (40.14%) and 85 workers aged 40 to 60 years (59.86%). The median blood aluminum level was 38.23 (interquartile range, 21.82) μg/L. The median cognitive function score was 24.00 (interquartile range, 3.00) points. Quantile regression analysis revealed that older age (βQ5=-0.186, 95%CI: -0.269 to -0.102), lower educational level (βQ5=1.933, 95%CI: 1.029 to 2.838; βQ10=1.743, 95%CI: 0.480 to 3.006; βQ50=1.038, 95%CI: 0.141 to 1.935; βQ75=1.006, 95%CI: 0.437 to 1.575; βQ90=1.111, 95%CI: 0.291 to 1.930), smoking (βQ5=-2.056, 95%CI: -3.264 to -0.849), alcohol consumption (βQ5=-1.821, 95%CI: -3.247 to -0.396) and higher blood aluminum level (βQ5=-0.075, 95%CI: -0.110 to -0.040; βQ10=-0.078, 95%CI: -0.127 to -0.029; βQ50=-0.075, 95%CI: -0.110 to -0.040; βQ75=-0.057, 95%CI: -0.079 to -0.035; βQ90=-0.067, 95%CI: -0.099 to -0.035) were associated with cognitive function decline among aluminum workers. Conclusions Educational level and blood aluminum level are the main factors affecting the cognitive function among aluminum workers. Among those with lower cognitive function scores, age, smoking and alcohol consumption are also associated with cognitive function.

Objective:To investigate the value of surgical classification and pelvic floor reconstruction in pelvic exenteration for locally recurrent or locally advanced rectal cancer. Methods:A retrospective descriptive study method was used.Perioperative data were collected from 67 consecutive patients with locally advanced or locally recurrent rectal cancer who underwent pelvic exenteration at the Department of Anorectal Surgery,the Second Affiliated Hospital of Navy Military Medical University between November 2021 and November 2022 through the Chinese Combined Pelvic Exenteration Case Database for rectal cancer.The surgical range was divided into two categories:mainly localized in the pelvic cavity(48 cases)and combined with resection of the main tissue of the pelvic wall(1 9 cases).Outcome indexes included:(1)preoperative general data of patients;(2)intraoperative conditions;(3)postoperative recovery and complications(postoperative complications were evaluated by international Clavien-Dindo classification);(4)follow-up(outpatient and telephone follow-up were used to understand the postoperative survival,tumor recurrence and metastasis of patients,and the follow-up time was up to February 28,2023 or the case died).Measurement data are expressed by median(range),and enumeration data are expressed by example(％). Results:In the pelvic resection group,the median age of 48 patients was 57.5 years(range:31-82 years);29 were males and 19 were females;26 of them had locally advanced rectal cancer and 22 had locally recurrent rectal cancer;39 had a history of chemotherapy,immunotherapy or targeted therapy,and 26 had a history of radiotherapy;the median operation time was 425 min(range:240-1 020 min);the median intraoperative blood loss was 500 mL(range:200-4 000 mL);the median time to recovery of intestinal function was 3 d(range:1-9 d);the median recovery time of empty pelvis syndrome was 25.3 d(range:5-105 d);43 patients had postoperative complications＜grade Ⅲ,and of the 5 patients with ≥ grade Ⅲcomplications,2 died of multiple organ failure 7 d after operation,2 patients had surgical hemostasis for massive hemorrhage of pelvic floor wounds after operation,and 1 patient recovered from postoperative respiratory failure after rescue.In the combined pelvic wall resection group,the median age of 1 9 patients was 54.5 years(range:43-76 years);9 were males and 10 were females;4 patients had locally advanced rectal cancer and 15 patients had locally recurrent rectal cancer,all of whom had a history of chemotherapy,immunotherapy or targeted therapy,and 1 5 patients had a history of radiotherapy;the median operation time was 580 min(range:360-960 min);the median intraoperative blood loss was 1 600 mL(range:400-4 000 mL);the median intestinal function recovery time was 3 d(range:2-7 d);the median empty pelvis syndrome recovery time was 62.3 d(range:7-120 d);15 patients had postoperative complications＜grade Ⅲ,and of the 4 patients with grade ≥ Ⅲ,3 patients had surgical hemostatis for postoperative pelvic floor wound bleeding and 1 patient recovered after the second operation for intestinal obstruction.As of February 28,2023 or death,67 patients were followed up for a median of 7.5 months(range:3-1 5 months),and 3 patients died 3-8 months after operation due to rapid tumor progression,severe urinary tract infection,and sudden heart disease during the follow-up period.The remaining 62 cases survived. Conclusion:The surgical classification has guiding significance for preoperative surgical planning in patients with locally advanced or locally recurrent rectal cancer who undergo combined pelvic exenteration,and the method of pelvic floor reconstruction based on biological mesh is safe and feasible in combined pelvic exenteration for locally advanced or locally recurrent rectal cancer.

Objectives:To analyze the factors relative to the short-term preservation of ipsilateral renal function after partial nephrectomy.Methods:The clinical data of 83 patients who were treated with partial nephrectomy from December 2014 to December 2019 in the Department of Urology, Sun Yat-sen University Cancer Center were retrospectively analyzed. There were 54 males and 29 females, aging ( M (IQR)) 49 (17) years (range: 27 to 74 years). The ischemia time in operation was 25 (18) minutes (range: 10 to 67 minutes). Emission computed tomography scan and CT scan were performed before (within 1 month) and after (3 to 12 months) surgery. The volume of the ipsilateral and contralateral kidney was measured on the basis of preoperative and postoperative CT scans. The glomerular filtration rate (GFR) specifically in each kidney was estimated by emission computed tomography. Recovery from ischemia is determined by the formula: GFR preservation/volume saved×100%. Linear regression was used to explore the factors ralative to the short-term preservation of ipsilateral renal function after partial nephrectomy. Results:The GFR preservation of the ipsilateral kidney was 80.9 (25.2) % (range: 31.0% to 109.4%). The volume loss of the kidney resulted in a decrease of 12.0% (5.8 ml/(min×1.96 m 2)) of GFR, while the ischemic injury resulted in a decrease of 6.5% (2.5 ml/(min×1.96 m 2)) of GFR. The volume saved from the ipsilateral kidney was 87.1 (12.9) % (range: 27.0% to 131.7%). Recovery from ischemia was 93.5 (17.5) % (range:44.3% to 178.3%). In multivariate analysis, GFR preservation of the ipsilateral kidney was significantly correlated with the volume saved of the ipsilateral kidney ( β=0.383, 95% CI: 0.144 to 0.622, P=0.002). It was not related to the ischemia time ( β=0.046, 95% CI:-0.383 to 0.475, P=0.831). Conclusion:In the condition of limited ischemic time, in the short term ipsilateral renal function after partial nephrectomy is mainly determined by the loss of kidney volume, while ischemic injury only plays a minor role.

Objectives:To analyze the factors relative to the short-term preservation of ipsilateral renal function after partial nephrectomy.Methods:The clinical data of 83 patients who were treated with partial nephrectomy from December 2014 to December 2019 in the Department of Urology, Sun Yat-sen University Cancer Center were retrospectively analyzed. There were 54 males and 29 females, aging ( M (IQR)) 49 (17) years (range: 27 to 74 years). The ischemia time in operation was 25 (18) minutes (range: 10 to 67 minutes). Emission computed tomography scan and CT scan were performed before (within 1 month) and after (3 to 12 months) surgery. The volume of the ipsilateral and contralateral kidney was measured on the basis of preoperative and postoperative CT scans. The glomerular filtration rate (GFR) specifically in each kidney was estimated by emission computed tomography. Recovery from ischemia is determined by the formula: GFR preservation/volume saved×100%. Linear regression was used to explore the factors ralative to the short-term preservation of ipsilateral renal function after partial nephrectomy. Results:The GFR preservation of the ipsilateral kidney was 80.9 (25.2) % (range: 31.0% to 109.4%). The volume loss of the kidney resulted in a decrease of 12.0% (5.8 ml/(min×1.96 m 2)) of GFR, while the ischemic injury resulted in a decrease of 6.5% (2.5 ml/(min×1.96 m 2)) of GFR. The volume saved from the ipsilateral kidney was 87.1 (12.9) % (range: 27.0% to 131.7%). Recovery from ischemia was 93.5 (17.5) % (range:44.3% to 178.3%). In multivariate analysis, GFR preservation of the ipsilateral kidney was significantly correlated with the volume saved of the ipsilateral kidney ( β=0.383, 95% CI: 0.144 to 0.622, P=0.002). It was not related to the ischemia time ( β=0.046, 95% CI:-0.383 to 0.475, P=0.831). Conclusion:In the condition of limited ischemic time, in the short term ipsilateral renal function after partial nephrectomy is mainly determined by the loss of kidney volume, while ischemic injury only plays a minor role.

Objective:To investigate the surface characterization,cell adhension and proliferation of ultrafine grained titanium (UFG Ti) after different sand blasting and acid-etching(SLA).Methods:The billets of UFG Ti and commercially pure titanium Ti(CP Ti) were incised into cylindrical specimens with 7 mm in diameter and 2 mm in height.The specimens were sand blasted at the air pressure of 0.2,0.4,0.6 and 0.8 MPa respectively(n =10) and then acid-etched.The surface morphology,roughness and surface wettability of the specimens were examined.Rat embryo osteoblasts MC3T3-E1 were cultured on the speciments for 1 d,3 d and 5 d respectively,the cell morphology and cell density were observed.Results:The different hierarchical porous topographies were formed on the surface of UFG and CP Ti after modified by SLA.The sizes of blasted holes on the surface and the surface roughness of both materials increased with the increase of blast pressure,but the values of UFG Ti were lower than those of CP Ti correspondingly(P ＜ 0.05).The surface wettability of them was also changed with the blast pressure,but the values of UFG Ti was significantly smaller than those of CP Ti(P ＜ 0.05).When the blast pressure was 0.6 Mpa,the UFG Ti exhibited excellent wettability,the cell density was the highest,the morphology of MC3T3-E1 cells on UFG Ti was superior to that on CP Ti.Conclusion:UFG Ti exhibits proper surface morphology,roughness and excellent wettability,which is more appropriate for adhension and proliferation of MC3T3-E1 cells after modification by SLA at blast pressure of 0.6 Mpa.

OBJECTIVEThe theory of strain energy density (SED) was combined with finite element analysis to investigate alveolar bone remodeling of the mandibular first molar with different levels of periodontal attachment under mastication loading.

METHODSThree-dimensional finite element models of the mandibular first molar with different levels of periodontal attachment were established. Based on SED theory, the user material subroutine (UMAT) (used by ABAQUS software) was developed by ourselves to simulate the remodeling process of mandibular bone. The stress distributions and bone density changes were analyzed under different mastication loading. The influence of loading magnitude on alveolar bone remodeling with different levels of periodontal attachment was investigated.

RESULTSThe results showed that the neck of buccal, lingual regions and root apex area experienced a higher stress. The stress and the density of alveolar bone increased gradually with the enhancing of the bite force at the beginning. Then the density would appear declining when the bite force exceeded the extreme load. The extreme load reduced from 420 N to 240 N with the periodontal attachment falling from normal to 1/2 of root length also. And the remodeling rate of the bone was faster as the loading increasing.

CONCLUSIONThe capability of the periodontal tissue for supporting the teeth will drop gradually as the periodontal attachment level dropping. And the decline of bone density also appeared in earlier time. The change of density is associated with mastication loading during the bone remodelling. And reducing the occlusal force properly to the molar with different attachment level is benefit for clinical treatment and prognosis of periodontal disease.

Bite Force ; Bone Density ; Bone Remodeling ; Finite Element Analysis ; Humans ; Mandible ; Mastication ; Models, Biological ; Molar ; Stress, Mechanical ; Tooth Root

Objective:To study the residual stress distribution through the thickness of bilayered dental ceramic subjected to thermal stress, in order to improve the restoration. Methods: The finite element model of bilayered dental ceramic was set up based on International Organization for Standardization(ISO) 96936:1999. The residual stresses were calculated in viscoelastic and elastic phases during cooling of dental ceramic to analyze the residual stress distribution. Results: The deformation of core was greater than the veneer ceramics during the cooling period of dental ceramic. The residual stress increased with the decreasing of the temperature approaching the interface of core and veneer ceramics. But it decreased with the increasing of the thickness of veneer ceramics.Conclusion: Thermal compatibility of core and veneer ceramics is very important to the residual stress distribution in the bilayered dental ceramic, which may benefit to All-ceramic restorations. The viscoelastic behavior of ceramic should be taken into account in the thermal compatibility.