Non-blinking and photostable upconverted luminescence from single lanthanide-doped nanocrystals

The development of probes for single-molecule imaging has dramatically facilitated the study of individual molecules in cells and other complex environments. Single-molecule probes ideally exhibit good brightness, uninterrupted emission, resistance to photobleaching, and minimal spectral overlap with cellular autofluorescence. However, most single-molecule probes are imperfect in several of these aspects, and none have been shown to possess all of these characteristics. Here we show that individual lanthanide-doped upconverting nanoparticles (UCNPs)—specifically, hexagonal phase NaYF₄ (β-NaYF₄) nanocrystals with multiple Yb³⁺ and Er³⁺ dopants—emit bright anti-Stokes visible upconverted luminescence with exceptional photostability when excited by a 980-nm continuous wave laser. Individual UCNPs exhibit no on/off emission behavior, or “blinking,” down to the millisecond timescale, and no loss of intensity following an hour of continuous excitation. Amphiphilic polymer coatings permit the transfer of hydrophobic UCNPs into water, resulting in individual water-soluble nanoparticles with undiminished photophysical characteristics. These UCNPs are endocytosed by cells and show strong upconverted luminescence, with no measurable anti-Stokes background autofluorescence, suggesting that UCNPs are ideally suited for single-molecule imaging experiments.     

Elemental diet as an adjuvant for patients with locally advanced gastrointestinal cancer receiving radiation therapy: a prospectively randomized study.

Thirty patients with locally advanced, nonresectable, nonmetastatic cancer in the peripancreatic region, stomach and colorectum-anus, to be treated with radiation therapy with or without adjuvant chemotherapy, were randomized to receive standard diet and either usual between-meal feedings or 300 calories tid of a high nitrogen elemental diet. Although weight loss associated with radiation therapy was not significantly reduced in those receiving the nutritional supplement, delayed hypersensitivity skin test responses tended to improve in patients receiving the elemental dietary supplement and to deteriorate in controls. Planned radiation therapy was completed in all nutritionally supported patients. One control patient expired shortly after treatment was halted abruptly, and three other control patients required rescue by total parenteral nutrition.     

“Then you raise them with Shirchoy or cookies”: Understanding influences on delayed dietary diversity among children in Tajikistan

Dietary diversity is a key component of infant and young child feeding (IYCF) as well as adult health. In Tajikistan, a predominantly rural, former Soviet country in Central Asia, we conducted formative research to identify barriers to dietary diversity and strategies for nutrition behaviour change. In Spring, 2016, mixed‐methods data collection took place across 13 villages in all five regions, collecting collaborative mapping; structured assessments of stores and markets; home visits for dietary recalls; food storage, preparation, and meal observations; focus groups with pregnant women, mothers of young children, fathers, and mothers‐in‐law; and in‐depth expert interviews with local nutrition and health influentials. Overall, maternal diet was adequate in terms of diversity (only 13% reported <5/10 food groups in the past 24 hr); however, only 42% of index children 6–24 months met WHO guidelines for diversity, and only 34% met minimum acceptable diet criteria. In addition to issues of poverty and food scarcity, qualitative data reveal many behavioural barriers to timely introduction of diverse complementary foods. Women's strategies focused on gradual introduction of household diet components, without regard for diversity or nutrition. Foods such as meat were seen as costly and thus inappropriate for IYCF, and food taboos (i.e., fresh vegetables) further reduced diversity. Infant food preparation methods such as grinding were seen as impractical, and many foods were withheld until children develop teeth. Possible nutrition education strategies include point‐of‐purchase campaigns to improve availability and appeal of IYCF‐friendly foods, as well as influencing other key household members through mosques, schools, and health care providers.     

A phase II trial of 5-fluorouracil, doxorubicin, mitomycin C, and leucovorin in advanced gastric carcinoma

To determine the feasibility and toxicity of combining leucovorin (CF) with a 5-fluorouracil (5-FU) combination chemotherapy regimen currently accepted by many as standard treatment for gastric cancer, CF (500 mg/m2) was administered in combination with the Georgetown 5-FU, doxorubicin, and mitomycin C (FAM) regimen. Thirty-two patients with advanced adenocarcinoma of the stomach were evaluable for toxicity and 26 patients with measurable disease were evaluable for response. Fifty-four percent of patients were previously treated with chemotherapy or radiation therapy. The response rate was 38% (95% confidence interval, 21% to 59%). The median duration of response was 6 months (range, 2 to 23+ months). The estimated median survival time was 6.8 months for patients with measurable disease and 11.5 months for all 32 patients. Although diarrhea is dose limiting when 5-FU and CF are administered weekly for 6 of 8 weeks, diarrhea occurred rarely on this combination regimen with 5-FU and CF administered only 4 of every 8 weeks. The dose-limiting toxicity of FAM-CF was cumulative myelosuppression, which also occurs with the standard FAM regimen. As a result, the administered dose intensity of 5-FU decreased as patients continued on study. Thus, a randomized comparison of FAM with FAM-CF would not determine whether CF modulation increases the efficacy of 5-FU when it is administered in optimal doses to patients with gastric cancer.     

Contextual and stress process factors associated with head and neck cancer caregivers’ physical and psychological well‐being

Head and neck cancer (HNC) caregivers are especially vulnerable to poor outcomes because the HNC patients are at high risk for physical and functional impairments. This study examines contextual and stress process variables potentially associated with HNC caregivers’ physical and psychological well‐being. Patient‐caregiver variables included socio‐demographics, primary stressors (caregiving, patient clinical characteristics, HNC‐related symptoms/dysfunction), secondary stressors (caregiver employment, childcare responsibilities and sleep duration <7 hr), appraisal, and response (physical activity). General linear models modeled caregiver well‐being, along with depression and anxiety. A total of 33 patient‐caregiver dyads were included. Most caregivers were female (81.8%) and patient spouses/partners (72.7%). Factors significantly associated with better caregiver physical well‐being included caregiver older age, <2 comorbidities, ≥7 hr of sleep, ≥3 days/week physical activity, and patient swallowing and speech dysfunction. Factors significantly associated with better caregiver mental health functioning were less patient social dysfunction and less perceived caregiving burden. Short nighttime sleep, higher caregiver burden, and <3 days/week physical activity were also significantly related to caregivers’ depression and anxiety. Results suggested caregiver behaviors and perceived burden, along with patient HNC concerns are linked with caregiver well‐being. These behavioral, cognitive, and patient factors should be incorporated into caregiver screening tools or targeted with behavioral interventions to improve caregiver well‐being.     

Understanding hospital referrals to home health agencies

Using resource dependency theory and transaction-cost economics theory, we examined the simultaneous effects of a vertical integration strategy and environmental complexity on home health agency (HHA) referrals by hospitals. Discharge data for calendar year 1990 from 61 Pennsylvania hospitals were analyzed. Using hospital ownership of home health agencies and urban versus rural location as the primary independent variables, a logistic regression model calculated the probability of HHA referral, after controlling for long-term care beds and patient characteristics. Results showed that HHA ownership was a significant predictor of home health referrals for both rural and urban hospitals, although the effect was greater for urban hospitals. These results suggest that hospitals are actively using referrals to home healthcare in response to environmental pressures. As these pressures increase, hospitals will benefit from tight linkages with home health providers.