Quantum dots have been used in biomedical research for imaging, diagnostics and sensing purposes. However, concerns over the cytotoxicity of their heavy metal constituents and conflicting results from in vitro and small animal toxicity studies have limited their translation towards clinical applications. Here, we show in a pilot study that rhesus macaques injected with phospholipid micelle-encapsulated CdSe/CdS/ZnS quantum dots do not exhibit evidence of toxicity. Blood and biochemical markers remained within normal ranges following treatment, and histology of major organs after 90 days showed no abnormalities. Our results show that acute toxicity of these quantum dots in vivo can be minimal. However, chemical analysis revealed that most of the initial dose of cadmium remained in the liver, spleen and kidneys after 90 days. This means that the breakdown and clearance of quantum dots is quite slow, suggesting that longer-term studies will be required to determine the ultimate fate of these heavy metals and the impact of their persistence in primates.

Background and Aim Helicobacter pylori (H. pylori) infection rates have been changing with different populations and geographic areas. We systematically evaluated the longitudinal trends in H. pylori prevalence in China over the past decades. Methods We performed a systematic review of literature reporting the prevalence of H. pylori infection in mainland China from 1990 to 2019 in the PubMed and China National Knowledge Infrastructure databases. We conducted a meta‐analysis of qualified studies using a random effects model to estimate the pooled prevalence with a 95% confidence interval (95%CI). Results A total of 412 eligible studies with 1 377 349 subjects were included. The pooled H. pylori prevalence was 44.2% (95%CI: 43.0–45.5%) in mainland China, with an estimated 589 million individuals infected with H. pylori. The prevalence was relatively high in the Northwest (51.8%, 95%CI: 47.5–56.1%), East (47.7%, 95%CI: 45.4–50.0%), and Southwest China (46.6%, 95%CI: 42.1–51.1%). The prevalence significantly decreased from 58.3% (95%CI: 50.7–65.5%) in the period 1983–1994 to 40.0% (95%CI: 38.2–41.8%) in the period 2015–2019. The prevalence increased with age, ranging from 28.0% (95%CI: 23.9–32.5%) in children and adolescents to 46.1% (95%CI: 44.5–47.6%) in adults. Conclusion Although the burden of H. pylori infections is still huge in China, the infection rate has been decreasing over the past decades. Targeted H. pylori eradication strategies may be considered in areas or populations with a high incidence of gastric cancer.

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Hydrophobins are available from natural resources only in milligram amounts. BASF succeeded in a recombinant production process, up-scaled to pilot plant production in kilogram scale. Strain and protein optimization by modulation of gene expression and generation of fusion proteins finally leads to two class I hydrophobins called H*Protein A and H*Protein B. By analytical ultracentrifugation, we confirm that the self-association of H*Proteins in solution is governed by their sequence, because oligomerization is induced by the same mechanisms (pH > 6, temperature >> 5 degrees C, concentration > 0.2 mg/ml) as for the well-known native hydrophobins SC3 and HFB II. Additionally, we established the triggering of structure formation by bridging with divalent ions and the stabilization of dimers and tetramers by monovalent ions or surfactants. This interplay with surfactants can be exploited synergistically: The capacity for emulsification of a 300 ppm standard surfactant solution is boosted from 0 to 100% by the addition of a mere 1 ppm of our new hydrophobins, with H*Protein A and H*Protein B having specific application profiles. This astonishing performance is rationalized by the finding that the same minute admixtures enhance significantly the interfacial elastic modulus, thus stabilizing interfaces against coalescence and phase separation.