Towards additive manufacturing oriented geometric modeling using implicit functions

Surface-based geometric modeling has many advantages in terms of visualization and traditional subtractive manufacturing using computer-numerical-control cutting-machine tools. However, it is not an ideal solution for additive manufacturing because to digitally print a surface-represented geometric object using a certain additive manufacturing technology, the object has to be converted into a solid representation. However, converting a known surface-based geometric representation into a printable representation is essentially a redesign process, and this is especially the case, when its interior material structure needs to be considered. To specify a 3D geometric object that is ready to be digitally manufactured, its representation has to be in a certain volumetric form. In this research, we show how some of the difficulties experienced in additive manufacturing can be easily solved by using implicitly represented geometric objects. Like surface-based geometric representation is subtractive manufacturing-friendly, implicitly described geometric objects are additive manufacturing-friendly: implicit shapes are 3D printing ready. The implicit geometric representation allows to combine a geometric shape, material colors, an interior material structure, and other required attributes in one single description as a set of implicit functions, and no conversion is needed. In addition, as implicit objects are typically specified procedurally, very little data is used in their specifications, which makes them particularly useful for design and visualization with modern cloud-based mobile devices, which usually do not have very big storage spaces. Finally, implicit modeling is a design procedure that is parallel computing-friendly, as the design of a complex geometric object can be divided into a set of simple shape-designing tasks, owing to the availability of shape-preserving implicit blending operations

Effectiveness of adjuvant traditional Chinese medicine on macrovascular invasion in patients with hepatocellular carcinoma: a real-world propensity score-matched study

The study aimed to investigate the potential of traditional Chinese medicine (TCM) in reducing the risk of macrovascular invasion (MVI) in Chinese patients with hepatocellular carcinoma (HCC). This retrospective analysis involved 2,267 HCC patients treated at our hospital. Propensity score (PS) matching was used to compare TCM users (n = 485) with non-users (n = 485) in terms of age, Barcelona Clinic Liver Cancer (BCLC) staging, type of treatment, and AFP. The impact of TCM on the hazard ratio (HR) of MVI was evaluated using a Cox multivariate regression model. The efficacy of TCM therapy on MVI was further examined using the log-rank test. The analysis revealed that TCM medication was a significant protective factor for MVI in HCC patients, as evidenced by the Cox analysis (adjusted HR = 0.496, 95% CI: 0.387–0.635, p < 0.001). After PS matching, the Kaplan-Meier curve demonstrated a lower occurrence rate of MVI in TCM users compared to non-users. The study findings suggest that TCM treatment has the potential to decrease the incidence of MVI in HCC patients, irrespective of etiology, BCLC staging, liver function, or treatment type. Notably, as the use of TCM increased, the percentage of MVI in patients showed a gradual decrease, indicating the potential of TCM therapy as a successful strategy for preventing MVI

Colorimetric and Fluorescent Dual-Mode Detection of Aflatoxin B1 Using Composite Nanomaterial

In this study, a highly sensitive portable platform with colorimetric and fluorescent dual-mode signal output for the detection of aflatoxin B1 (AFB1) was developed based on the reaction between glutathione and a composite nanomaterial consisting of manganese dioxide (MnO2) nanoparticles and graphene quantum dots (GQDs) as a substrate. The recognition probe was prepared by using silica nanoparticles as a carrier to enrich glutathione and AFB1 aptamers. Under optimal conditions, analytical figures of merit such as specificity of this method were studied. The regression equation for colorimetric signal was ΔA = − 0.275 − 0.021lgC and the detection limit was 2.732 × 10-12 g/mL; the regression equation for fluorescence signal was ΔF = 928.733 + 71.779lgC and the detection limit was 1.667 × 10-12 g/mL. Both methods had good detection specificity. The proposed method was applied in the detection of food samples, such as milk, rice, oatmeal, soy sauce and white vinegar with higher accuracy, compared with the traditional method

Nicotinamide reverses deficits in puberty-born neurons and cognitive function after maternal separation.

Background Early life stress (ELS) is associated with the development of schizophrenia later in life. The hippocampus develops significantly during childhood and is extremely reactive to stress. In rodent models, ELS can induce neuroinflammation, hippocampal neuronal loss, and schizophrenia-like behavior. While nicotinamide (NAM) can inhibit microglial inflammation, it is unknown whether NAM treatment during adolescence reduces hippocampal neuronal loss and abnormal behaviors induced by ELS. Methods Twenty-four hours of maternal separation (MS) of Wistar rat pups on post-natal day (PND)9 was used as an ELS. On PND35, animals received a single intraperitoneal injection of BrdU to label dividing neurons and were given NAM from PND35 to PND65. Behavioral testing was performed. Western blotting and immunofluorescence staining were used to detect nicotinamide adenine dinucleotide (NAD+)/Sirtuin3 (Sirt3)/superoxide dismutase 2 (SOD2) pathway-related proteins. Results Compared with controls, only MS animals in the adult stage (PND56–65) but not the adolescent stage (PND31–40) exhibited pre-pulse inhibition deficits and cognitive impairments mimicking schizophrenia symptoms. MS decreased the survival and activity of puberty-born neurons and hippocampal NAD+ and Sirt3 expression in adulthood. These observations were related to an increase in acetylated SOD2, microglial activation, and significant increases in pro-inflammatory IL-1β, TNF-α, and IL-6 expression. All the effects of MS at PND9 were reversed by administering NAM in adolescence (PND35–65). Conclusions MS may lead to schizophrenia-like phenotypes and persistent hippocampal abnormalities. NAM may be a safe and effective treatment in adolescence to restore normal hippocampal function and prevent or ameliorate schizophrenia-like behavior

The Effect of aerobic exercise interventions on depression and depressive disorder in elderly. : A descriptive literature review

Background: Depression manifests as neurological and psychiatric disorders.Depression is a kind of emotional disorder accompanied by mental retardation symptoms,but also can lead to a variety of functional physical disorders.It can be gradual, can besudden.Its development process varies from person to person, affects people'spsychological and physiological, decreases people's quality of life.Depression is theleading cause of death among the elderly, and the prevalence rate is rising rapidly. Somestudies have shown that aerobic exercise interventions can decrease depression anddepressive disorder in elderly.Aim: To describe the effect of aerobic exercise intervention on depression anddepressive disorder in the elderly.Method: Quantitative literature search was conducted using keywords input fromPubMed and CINAHL databases to understand the influence of aerobic exerciseintervention on depression and depressive disorder in the elderly, and the results wereanalyzed and discussed.Result: Nine studies that met inclusion criteria were included in the review through acomprehensive search. These reviews found that different aerobic interventions, such asyoga, walking and high-intensity progressive exercise, can contribute to depression inelderly. Yoga and high-intensity progressive exercise are often used. In addition, the mostcommonly used duration of intervention was found to be 24 weeks.Conclusion: The review suggests that aerobic exercise interventions can effectivelydecrease depression, depressive disorder and anxiety and improve quality of life in elderly.This suggests that aerobic exercise interventions can be used in clinical care of elderlywith depression or depressive disorder. However, this finding comes from a number ofrandomized controlled studies, some of which have limitations, such as not beingcomprehensive and having a small sample size. To improve effectiveness, more researchis needed to explore further.Keywords: Aerobic exercise intervention, elderly, depression, depressive disorder

The Effect of aerobic exercise interventions on depression and depressive disorder in elderly. : A descriptive literature review

Background: Depression manifests as neurological and psychiatric disorders.Depression is a kind of emotional disorder accompanied by mental retardation symptoms,but also can lead to a variety of functional physical disorders.It can be gradual, can besudden.Its development process varies from person to person, affects people'spsychological and physiological, decreases people's quality of life.Depression is theleading cause of death among the elderly, and the prevalence rate is rising rapidly. Somestudies have shown that aerobic exercise interventions can decrease depression anddepressive disorder in elderly.Aim: To describe the effect of aerobic exercise intervention on depression anddepressive disorder in the elderly.Method: Quantitative literature search was conducted using keywords input fromPubMed and CINAHL databases to understand the influence of aerobic exerciseintervention on depression and depressive disorder in the elderly, and the results wereanalyzed and discussed.Result: Nine studies that met inclusion criteria were included in the review through acomprehensive search. These reviews found that different aerobic interventions, such asyoga, walking and high-intensity progressive exercise, can contribute to depression inelderly. Yoga and high-intensity progressive exercise are often used. In addition, the mostcommonly used duration of intervention was found to be 24 weeks.Conclusion: The review suggests that aerobic exercise interventions can effectivelydecrease depression, depressive disorder and anxiety and improve quality of life in elderly.This suggests that aerobic exercise interventions can be used in clinical care of elderlywith depression or depressive disorder. However, this finding comes from a number ofrandomized controlled studies, some of which have limitations, such as not beingcomprehensive and having a small sample size. To improve effectiveness, more researchis needed to explore further.Keywords: Aerobic exercise intervention, elderly, depression, depressive disorder

Ewolucja rozkładu wskaźników urodzeń według płci w prowincji Henan w Chinach

The imbalance in the ratio of males to females at birth is one of the major challenges facing modern China. It is a problem that cannot be overlooked, especially in the context of the socioeconomic development being experienced in China. Based on data of the sex ratio at birth in 2000 and 2010, and using exploratory spatial data analysis and geographical detector methods, this paper systematically explores spatial patterns, evolutionary characteristics and the mechanisms for the analysis of this ratio in Henan province. The results show that: (1) the degree of imbalance between the sexes is exhibiting a downward trend, while significant differences in the levels exist in internal county units and these variations are increasingly expanding; (2) areas exhibiting extreme levels of imbalance are located in the north, east and south of Henan. The remaining areas had a mixed distribution and were widely spread in the central and western regions of the province; (3) according to the spatial correlation characteristics, there exists an obvious aggregation phenomenon in sex structure at birth which has moved northwest in the decade under review; and (4) there are many factors affecting the distribution of the ratio between the sexes at birth, including natural environmental conditions, levels of education, population stress, economic development and population migration. In addition to these factors, urbanization, living conditions, social development, traffic conditions, income level, reproductive potential and health factors have also influenced the proportion of males to females to different degrees.Dysproporcje w liczbie urodzeń mężczyzn w stosunku do liczby urodzeń kobiet stanowią jedno z głównych wyzwań współczesnych Chin. Jest to problem, który nie może zostać pominięty, szczególnie w kontekście trwającego w Chinach rozwoju społeczno-gospodarczego. Niniejszy artykuł podejmuje metodyczną analizę wzorców przestrzennych, cech ewolucyjnych i mechanizmów analizy wskaźnika urodzeń według płci w prowincji Henan w oparciu o dane z lat 2000 i 2010 oraz z wykorzystaniem danych przestrzennych i metod detekcji geograficznej. Wyniki badań pokazują, że: (1) stopień dysproporcji pomiędzy liczbą urodzeń według płci wykazuje tendencję spadkową, a znaczne, coraz bardziej widoczne, różnice istnieją w wewnętrznych jednostkach powiatowych prowincji; (2) północne, wschodnie i południowe obszary prowincji Henan odznaczają się najwyższym stopniem tych dysproporcji. W pozostałych obszarach prowincji dysproporcje rozkładały się w sposób mieszany i były szeroko rozpowszechnione w regionach centralnych oraz zachodnich; (3) zgodnie ze specyfiką korelacji przestrzennej, istnieje oczekiwane zjawisko agregacji w strukturze urodzeń według płci, które na przestrzeni dekady przemieściło się w rejon północnego-zachodu; (4) istnieje wiele czynników, które mają wpływ na rozkład proporcji płci podczas narodzin, należą do nich: warunki naturalne, poziom wykształcenia, poziom stresu ludności oraz rozwoju gospodarczego, migracja ludności. Oprócz powyższych czynników, wpływ na odsetek mężczyzn wśród kobiet miały w różnym stopniu: urbanizacja, panujące warunki mieszkaniowe, potencjał reprodukcyjny oraz czynniki zdrowotne

Evolution of pore structure and fractal characteristics of marine shale during electromagnetic radiation.

Electromagnetic radiation has been proposed to non-aqueously stimulate shale formations, which can generate fractures and enhance the porosity of the matrix. The proposed method consumes electricity and thereby possesses significant advantages for sustainable and environmental hydrocarbon production. In this study, we investigate the pore structure variations of marine shale during electromagnetic radiation. First, the prepared marine shale samples are exposed to electromagnetic radiation for different times; an infrared thermometer monitors the temperatures. Then, the nitrogen adsorption/desorption technique is applied to examine the evolutions of the pore structure. Next, a scanning electron microscope is adopted to reveal the morphology and identify newly developed pores. Lastly, fractal analyses are performed to quantify pore structure variations. The sample exhibits quick temperature rises, whose temperature reaches about 300 °C after 5 min of electromagnetic radiation. The elevated temperature causes clay dehydration, thermal expansion, and organic matter decomposition, leading to significant changes in pore structures. The nitrogen adsorption/desorption characteristics demonstrate enhancements in pore spaces, including volume, size, and surface area. Fractal analyses show that the pores become rougher and exhibit less heterogeneity after electromagnetic radiation. The obtained results demonstrate a great potential of using electromagnetic radiation to enhance the porosity of shale rocks