Dimensionality engineering of metal halide perovskites.

Metal halide perovskites are a class of materials that are ideal for photodetectors and solar cells due to their excellent optoelectronic properties. Their low-cost and low temperature synthesis have made them attractive for extensive research aimed at revolutionizing the semiconductor industry. The rich chemistry of metal halide perovskites allows compositional engineering resulting in facile tuning of the desired optoelectronic properties. Moreover, using different experimental synthesis and deposition techniques such as solution processing, chemical vapor deposition and hot-injection methods, the dimensionality of the perovskites can be altered from 3D to 0D, each structure opening a new realm of applications due to their unique properties. Dimensionality engineering includes both morphological engineering-reducing the thickness of 3D perovskite into atomically thin films-and molecular engineering-incorporating long-chain organic cations into the perovskite mixture and changing the composition at the molecular level. The optoelectronic properties of the perovskite structure including its band gap, binding energy and carrier mobility depend on both its composition and dimensionality. The plethora of different photodetectors and solar cells that have been made with different compositions and dimensions of perovskite will be reviewed here. We will conclude our review by discussing the kinetics and dynamics of different dimensionalities, their inherent stability and toxicity issues, and how reaching similar performance to 3D in lower dimensionalities and their large-scale deployment can be achieved.

Joint curettage arthrodesis technique in the foot: a histological analysis.

UNLABELLED: Arthrodesis via joint contour preservation using the curettage method has become popular in foot and ankle surgery to avoid segmental shortening and the need to bone graft. Despite its popularity, the effect of joint curettage has never been histologically evaluated. Knowledge of the histological appearance after joint curettage would be helpful to the foot and ankle surgeon to better understand the function of joint surface preparation for arthrodesis. Five cadaver specimens were used to harvest the first metatarsocuneiform and subtalar joints for routine histological analysis after performing joint curettage technique. One specimen was used as a reference, whereas the remaining specimens were processed after joint surface preparation. Results show a residual layer of calcified cartilage overlying the subchondral plate interface on all osteochondral specimens after joint curettage. This suggests there is a natural histological barrier that may interfere with arthrodesis consolidation. LEVEL OF CLINICAL EVIDENCE: 5.

Fatal Balamuthia mandrillaris brain infection associated with improper nasal lavage.

We report the case of a 69-year-old female who presented with a chronic nasal skin rash, new onset focal seizure, and a cerebral ring-enhancing lesion after a year of improper nasal irrigation. Despite aggressive and novel anti-amoebic treatment, she died as a result of a Balamuthia mandrillaris brain infection.

Comparison of breast cancer to healthy control tissue discovers novel markers with potential for prognosis and early detection.

This study was initiated to identify biomarkers with potential value for the early detection of poor-outcome breast cancer. Two sets of well-characterized tissues were utilized: one from breast cancer patients with favorable vs. poor outcome and the other from healthy women undergoing reduction mammaplasty. Over 46 differentially expressed genes were identified from a large list of potential targets by a) mining publicly available expression data (identifying 134 genes for quantitative PCR) and b) utilizing a commercial PCR array. Three genes show elevated expression in cancers with poor outcome and low expression in all other tissues, warranting further investigation as potential blood markers for early detection of cancers with poor outcome. Twelve genes showed lower expression in cancers with poor outcome than in cancers with favorable outcome but no differential expression between aggressive cancers and most healthy controls. These genes are more likely to be useful as prognostic tissue markers than as serum markers for early detection of aggressive disease. As a secondary finding was that, when histologically normal breast tissue was removed from a distant site in a breast with cancer, 7 of 38 specimens displayed a cancer-like expression profile, while the remaining 31 were genetically similar to the reduction mammaplasty control group. This finding suggests that some regions of ipsilateral histologically 'normal' breast tissue are predisposed to becoming malignant and that normal-appearing tissue with malignant signature might warrant treatment to prevent new primary tumors.