Sub-100 mA/cm2 CO2-to-CO Reduction Current Densities in Hierarchical Porous Gold Electrocatalysts Made by Direct Ink Writing and Dealloying.

While most research efforts on CO2-to-CO reduction electrocatalysts focus on boosting their selectivity, the reduction rate, directly proportional to the reduction current density, is another critical parameter to be considered in practical applications. This is because mass transport associated with the diffusion of reactant/product species becomes a major concern at a high reduction rate. Nanostructured Au is a promising CO2-to-CO reduction electrocatalyst for its very high selectivity. However, the CO2-to-CO reduction current density commonly achieved in conventional nanostructured Au electrocatalysts is relatively low (in the range of 1-10 mA/cm2) for practical applications. In this work, we combine direct ink writing-based additive manufacturing and dealloying to design a robust hierarchical porous Au electrocatalyst to improve the mass transport and achieve high CO2-to-CO reduction current densities on the order of 64.9 mA/cm2 with CO partial current density of 33.8 mA/cm2 at 0.55 V overpotential using an H-cell configuration. Although the current density achieved in our robust hierarchical porous Au electrocatalyst is one order of magnitude higher than the one achieved in conventional nanostructured electrocatalysts, we found that the selectivity of our system is relatively low, namely 52%, which suggests that mass transport remains a critical issue despite the hierarchical porous architecture. We further show that the bulk dimension of our electrocatalyst is a critical parameter governing the interplay between selectivity and reduction rate. The insights gained in this work shed new light on the design of electrocatalysts toward scale-up CO2 reduction and beyond.

Variations in intrinsic breast cancer characteristics in screen-detected breast cancer patients aged between 45 and 69 and above the age of 70.

BACKGROUND: Increasing age is a well-recognized risk factor for breast cancer. With an increase in life expectancy of women, more older patients are diagnosed with breast cancer. This study aimed to identify the variations in breast cancer attributes and mortality in different age groups in New Zealand. METHODS: This was a retrospective study of data from the Auckland Breast Cancer Register between 1 June 2000 and 28 February 2017. Patients who were diagnosed through Breast Screen were included. Group A included those aged between 45 and 69 years. Group B included individuals with an age of 70 years or above. RESULTS: From June 2000 to February 2017, a total of 6304 new cases of new breast cancer were diagnosed through Auckland Breast Screen, with 5788 patients in group A and 516 patients in group B. Group B was more likely to have the lower grade invasive cancers, with fewer grade 3 cancers. Oestrogen receptor positivity was more pronounced in group B, along with progesterone receptor positivity. Conversely, HER-2 receptor was less likely to be positive in group B. There was a significantly higher breast cancer-related mortality in group B (6.0% versus 2.7%). Mortality related to other causes was also much higher in group B as compared to that in group A (12.8% versus 2.5%). CONCLUSION: Women aged 70 years or above generally tend to have a more favourable type of breast cancer, with a lower tumour grade, oestrogen and progesterone receptor positivity, and lower rate of HER-2 overexpression.

An electrochemical biosensor exploiting binding-induced changes in electron transfer of electrode-attached DNA origami to detect hundred nanometer-scale targets.

The specific detection in clinical samples of analytes with dimensions in the tens to hundreds of nanometers, such as viruses and large proteins, would improve disease diagnosis. Detection of these "mesoscale" analytes (as opposed to their nanoscale components), however, is challenging as it requires the simultaneous binding of multiple recognition sites often spaced over tens of nanometers. In response, we have adapted DNA origami, with its unparalleled customizability to precisely display multiple target-binding sites over the relevant length scale, to an electrochemical biosensor platform. Our proof-of-concept employs triangular origami covalently attached to a gold electrode and functionalized with redox reporters. Electrochemical interrogation of this platform successfully monitors mesoscale, target-binding-induced changes in electron transfer in a manner consistent with coarse-grained molecular dynamics simulations. Our approach enables the specific detection of analytes displaying recognition sites that are separated by ∼40 nm, a spacing significantly greater than that achieved in similar sensor architectures employing either antibodies or aptamers.

Extending Screening in "Elderly" Patients: Should We Consider a Selective Approach?

BACKGROUND: Breast cancer screening has been shown to reduce breast cancer-associated mortality. However, screening is limited to the targeted age group of 45 to 69 years in New Zealand despite the recognized increased risk with age. This study aims to compare the outcomes of women aged over 70 years with screen-detected and clinically detected cancers. PATIENTS AND METHODS: A retrospective review was performed of prospectively collected data from June 2000 to May 2013 by the Auckland Breast Cancer Register. Demographic and tumor characteristics of women with invasive cancer and ductal carcinoma in situ diagnosis aged 70 years and over were compared between those screened and clinically detected. Five-year disease-free and overall survival outcomes were reviewed. RESULTS: A total of 2128 women aged 70 years and over were diagnosed with breast cancer (median, 77 years; interquartile range [IQR], 74-84 years). Of these, 416 (19.5%) were diagnosed through mammography screening, with a median age of 74 years (IQR, 71-77 years) compared with 79 years (IQR, 74-85 years) for those with clinical detected cancer diagnosis. Screen-detected cancers accounted for a significantly higher proportion of diagnoses in those aged 70 to 74 years compared with older patients (P < .001). Screen-detected cancers were of lower T and N stages. Disease-specific survival was significantly longer in screen-detected cancers versus other cancers (5-year survival, 93.7% vs. 81.9%; P < .001), as was overall survival (5-year survival, 84.7% vs. 57.4%; P < .001). CONCLUSION: Screening in those aged 70 years and over continues to identify breast cancer at early stages and with improved survival. Although aware of the potential for lead-time bias and the healthy volunteer effect, there should still be consideration to extend breast cancer screening to patients aged to up 74 years after appropriate assessment of comorbidities and functional status.

Influence of the new AJCC breast cancer staging system on sentinel lymph node positivity and false-negative rates.

The sixth and newest edition of the American Joint Committee on Cancer (AJCC) staging system for breast cancer now defines axillary sentinel lymph nodes with micrometastatic deposits 0.2 mm in diameter or smaller as node-negative. The aim of this study was to determine how this new classification scheme would affect axillary sentinel lymph node positivity, false-negative rate, and overall accuracy of an inception cohort of 205 breast cancer patients undergoing definitive surgery that included sentinel lymph node biopsy plus level I/II axillary lymphadenectomy. Based on the previous AJCC system for staging breast cancer, in which all sentinel lymph node metastases were considered positive, the rate of nodal positivity in this cohort was 47%, the overall accuracy was 99%, and the false-negative rate was 2.1%. According to the new classification system, the rate of nodal positivity in this cohort was 39.5% and the overall accuracy was 98%. The false-negative rate rose to 4.9% because two patients with micrometastatic deposits 0.2 mm or smaller, which are considered node-negative in the new system, had macroscopically positive disease in non-sentinel lymph nodes found in the completion lymphadenectomy.

Intra-abdominal free fluid without solid organ injury in blunt abdominal trauma: an indication for laparotomy.

BACKGROUND: The optimal management of patients sustaining blunt abdominal trauma (BAT), in whom intra-abdominal free fluid but no solid organ injury is found on imaging, remains unclear. The purpose of this study was to determine the incidence and significance of this finding. METHODS: All patients presenting with suspected BAT to a provincial trauma center over a 30-month period were reviewed. A screening focused abdominal sonogram for trauma scan was obtained in every case. Stable patients with positive or indeterminate scans underwent computed tomographic scanning. Those with free fluid but without visible solid organ injury were studied. Radiologic interpretation, clinical management, and operative findings were analyzed. RESULTS: Twenty-eight of 1,367 patients (2%) met inclusion criteria. Twenty-one patients (75%) underwent exploratory laparotomy, which for 16 (76%) was therapeutic: bowel injuries were found in 10 patients, mesentery injuries in 6, and injuries to solid organs in 3. In five patients, laparotomy was nontherapeutic. Those with more than a trace of free fluid were significantly more likely to have a therapeutic procedure. Seven patients (25%) were observed, of whom two failed nonoperative management and underwent therapeutic laparotomies within 24 hours of admission for missed colon, splenic, and hepatic injuries. The presence of abdominal seat belt bruising or a Chance-type fracture in the study patients was associated with a 90% and 100% therapeutic laparotomy rate, respectively. Computed tomographic scan findings were variable and were not able to predict injury severity or need for surgery. CONCLUSION: The finding of more than trace amounts of free fluid in the absence of solid organ injury in BAT is often associated with clinically significant visceral injury. Early laparotomy is recommended for these patients.