ABSTRACT
The practical applications of metallic anodes are limited due to dendritic growth, propagation in an infinite volume during the plating process, and parasitic interfacial reactions between sodium (Na) and the electrolyte. Herein, we developed Sb2S3 microrods as a template to regulate the nucleation of metallic Na. Additionally, the propagation of the deposited metal could be spatially regulated via a "nanoconfinement effect", that is, within the conformal hard carbon (C) layer of nanothickness. Moreover, we carefully studied the seed effect of the in situ-formed Na-Sb and Na-S alloys within the hard C sheath during the Na plating process. The symmetrical cells of the Sb2S3@C composite anode achieved dendrite-free cycling at 1 mA cm-2 for 1100 h at a high capacity loading of 1 mA h cm-2 and considerably mitigated a nucleation overpotential of 20 mV. Pairing a NaVPO4F (NVPF) cathode (4.6 mg cm-2) with an in situ presodiation Sb2S3@C composite (2*Na excess) prototype delivered a high energy density and a high power density of 173.75 W h kg-1 and 868.57 W kg-1, respectively. Therefore, this study provides tremendous possibilities for employing the proposed hybrid storage mechanism in low-cost and practical applications of high-energy-density Na metal batteries.
ABSTRACT
BACKGROUND: There is strong evidence that delayed diagnosis of breast cancer is associated with poor survival. The objectives were to determine the frequency of breast cancer patients with delayed presentation, the reasons of delay and its association with different socio-demographic variables in our settings. METHODS: We interviewed 315 histologically confirmed breast cancer patients. Delay was defined as more than 3 months from appearance of symptoms to the consultation from doctor. Questions were asked from each patient which could reflect their understanding about the disease and which could be the likely reasons for their delayed presentation. RESULTS: A total of 39.01% (n=123) of patients presented late and out of those, 40.7% wasted time using alternative medicines; 25.2% were not having enough resources; 17.1% presented late due to painless lump; 10.6% felt shyness and 6.5% presented late due to other reasons. Higher age, negative family history, <8 school years of education and low to middle socio-economic status were significantly associated with delayed presentation (P<0.05). Education and socioeconomic status were two independent variables related to the delayed presentation after adjustment for others [odds ratios (OR) of 2.26, 2.29 and 95% confidence intervals (CI) was 1.25-4.10, 1.06-4.94 respectively]. CONCLUSIONS: Significant percentage of women with breast cancer in North Pakistan is experiencing presentation delay due to their misconceptions about the disease. Coordinated efforts with public health department are needed to educate the focused groups and mitigating the barriers identified in the study. Long term impact will be reduced overall burden of the disease in the region.
ABSTRACT
BACKGROUND: There is strong evidence that delayed diagnosis of breast cancer is associated with poor survival. Our objectives were to determine the frequency of breast cancer patients with delayed presentation, the reasons of delay and its association with different socio-demographic variables in our North Pakistan setting. MATERIALS AND METHODS: We interviewed 315 histologically confirmed breast cancer patients. Delay was defined as more than 3 months from appearance of symptoms to consultation with a doctor. Questions were asked from each patient which could reflect their understanding about the disease and which could be the likely reasons for their delayed presentation. RESULTS: 39.0 % (n=123) of patients presented late and out of those, 40.7% wasted time using alternative medicines; 25.2 % did not having enough resources; 17.1 % presented late due to painless lump; 10.6% felt shyness and 6.5% presented late due to other reasons. Higher age, negative family history, < 8 school years of education and low to middle socio-economic status were significantly associated with delayed presentation (p< 0.05). Education and socioeconomic status were two independent variables related to the delayed presentation after adjustment for others (OR of 2.26, 2.29 and 95%CI was 1.25-4.10, 1.06-4.94 respectively). CONCLUSIONS: Significant numbers of women with breast cancer in North Pakistan experience presentation delay due to their misconceptions about the disease. Coordinated efforts with public health departments are needed to educate the focused groups and removing the barriers identified in the study. Long term impact will be reduced overall burden of the disease in the region.
