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Electrical interactions between bacteria and the environment are delicate and essential. In this study, an external electrical current is applied to capacitive titania nanotubes doped with carbon (TNT-C) to evaluate the effects on bacteria killing and the underlying mechanism is investigated. When TNT-C is charged, post-charging antibacterial effects proportional to the capacitance are observed. This capacitance-based antibacterial system works well with both direct and alternating current (DC, AC) and the higher discharging capacity in the positive DC (DC+) group leads to better antibacterial performance. Extracellular electron transfer observed during early contact contributes to the surface-dependent post-charging antibacterial process. Physiologically, the electrical interaction deforms the bacteria morphology and elevates the intracellular reactive oxygen species level without impairing the growth of osteoblasts. Our finding spurs the design of light-independent antibacterial materials and provides insights into the use of electricity to modify biomaterials to complement other bacteria killing measures such as light irradiation. Bacteria are known to be sensitive to electrical interactions with the environment. Here, the authors report on a study into how the antibacterial properties of carbon-doped titania nanotubes are affected by capacitance after charging with direct and alternating currents.

After exhibiting an upward trend since 1979, Antarctic sea ice extent (SIE) declined dramatically during austral spring 2016, reaching a record low by December 2016. Here we show that a combination of atmospheric and oceanic phenomena played primary roles for this decline. The anomalous atmospheric circulation was initially driven by record strength tropical convection over the Indian and western Pacific Oceans, which resulted in a wave-3 circulation pattern around Antarctica that acted to reduce SIE in the Indian Ocean, Ross and Bellingshausen Sea sectors. Subsequently, the polar stratospheric vortex weakened significantly, resulting in record weakening of the circumpolar surface westerlies that acted to decrease SIE in the Indian Ocean and Pacific Ocean sectors. These processes appear to reflect unusual internal atmosphere-ocean variability. However, the warming trend of the tropical Indian Ocean, which may partly stem from anthropogenic forcing, may have contributed to the severity of the 2016 SIE decline. Antarctic sea ice extent declined dramatically in austral spring 2016. This study shows the decline was initially driven by tropical convection resulting in a wave-3 circulation pattern, followed by weakened circumpolar surface westerlies initialised in the polar stratospheric vortex.

Velocardiofacial syndrome (VCFS) is a disease in human with an expansive phenotypic spectrum and diverse genetic mechanisms mainly associated with copy number variations (CNVs) on 22q11.2 or other chromosomes. However, the correlations between CNVs and phenotypes remain ambiguous. This study aims to analyze the types and sizes of CNVs in VCFS patients, to define whether correlations exist between CNVs and clinical manifestations in Chinese VCFS patients. In total, 55 clinically suspected Chinese VCFS patients and 100 normal controls were detected by multiplex ligation-dependent probe amplification (MLPA). The data from MLPA and all the detailed clinical features of the objects were documented and analyzed. A total of 44 patients (80.0%) were diagnosed with CNVs on 22q11.2. Among them, 43 (78.2%) presented with 22q11.2 heterozygous deletions, of whom 40 (93.0%) had typical 3-Mb deletion, and 3 (7.0%) exhibited proximal 1.5-Mb deletion; no patient was found with atypical deletion on 22q11.2. One patient (1.8%) presented with a 3-Mb duplication mapping to the typical 3-Mb region on 22q11.2, while none of the chromosomal abnormalities in the MLPA kit were found in the other 11 patients and 100 normal controls. All the 43 patients with 22q11.2 deletions displayed characteristic face and palatal anomalies; 37 of them (86.0%) had cognitive or behavioral disorders, and 23 (53.5%) suffered from immune deficiencies; 10 patients (23.3%) manifested congenital heart diseases. Interestingly, all patients with the characteristic face had 22q11.2 heterozygous deletions, but no difference in phenotypic spectrum was observed between 3-Mb and 1.5-Mb deletions. Our data suggest that the characteristic face can be used as a key indicator for direct diagnosis of 22q11.2 deletions in Chinese VCFS patients.

This study offers an overview of the low-frequency (i.e., monthly to seasonal) evolution, dynamics, predictability, and surface impacts of a rare Southern Hemisphere (SH) stratospheric warming that occurred in austral spring 2019. Between late August and mid-September 2019, the stratospheric circumpolar westerly jet weakened rapidly, and Antarctic stratospheric temperatures rose dramatically. The deceleration of the vortex at 10 hPa was as drastic as that of the first-ever-observed major sudden stratospheric warming in the SH during 2002, while the mean Antarctic warming over the course of spring 2019 broke the previous record of 2002 by ~50% in the midstratosphere. This event was preceded by a poleward shift of the SH polar night jet in the uppermost stratosphere in early winter, which was then followed by record-strong planetary wave-1 activity propagating upward from the troposphere in August that acted to dramatically weaken the polar vortex throughout the depth of the stratosphere. The weakened vortex winds and elevated temperatures moved downward to the surface from mid-October to December, promoting a record strong swing of the southern annular mode (SAM) to its negative phase. This record-negative SAM appeared to be a primary driver of the extreme hot and dry conditions over subtropical eastern Australia that accompanied the severe wildfires that occurred in late spring 2019. State-of-the-art dynamical seasonal forecast systems skillfully predicted the significant vortex weakening of spring 2019 and subsequent development of negative SAM from as early as late July.

Australia typically experiences drought during El Niño, especially across the eastern two-thirds of the continent during austral spring (September–November). There have, however, been some interesting departures from this paradigm. For instance, the near-record-strength El Niño of 1997 was associated with near-normal rainfall. In contrast, eastern Australia experienced near-record drought during the modest El Niño of 2002. This stark contrast raises the issue of how the magnitude of the drought is related to the character and magnitude of El Niño, for instance as measured by the broadscale sea surface temperature (SST) anomaly in the equatorial eastern Pacific. Internal (unpredictable) atmospheric noise is one plausible explanation for this contrasting behavior during these El Niño events. Here, the authors suggest that Australian rainfall is sensitive to the zonal distribution of SST anomalies during El Niño and, in particular, the greatest sensitivity is to the SST variations on the eastern edge of the Pacific warm pool rather than in the eastern Pacific where El Niño variations are typically largest. Positive SST anomalies maximized near the date line in 2002, but in 1997 maximum anomalies were shifted well into the eastern Pacific, where their influence on Australian rainfall appears to be less. These findings provide a plausible physical basis for the view that forecasting the strength of El Niño is not sufficient to accurately predict rainfall variations across Australia during El Niño.

Predictive skill for El Niño in the equatorial eastern Pacific across a range of forecast models declined sharply in the early twenty-first century relative to what was achieved in the late twentieth century despite ongoing improvements of forecast systems. This decline coincided with a shift in Pacific climate to an enhanced east–west surface temperature gradient across the Pacific and a stronger Walker circulation at the end of the twentieth century. Using seasonal forecast sensitivity experiments with the Australian Bureau of Meteorology coupled model POAMA2.4, the authors show that this shift in background climate acted to weaken key ocean–atmosphere feedbacks that amplify eastern Pacific El Niño, thus resulting in weaker variability that is less predictable. These results indicate that extreme El Niños, such as those that occurred in 1982/83 and 1997/98,were conditioned by the background climate and so were favored to occur in the late twentieth century. However, anticipating future changes in El Niño variability and predictability is an outstanding challenge because causes and prediction of low-frequency variations of Pacific climate have not yet been demonstrated.

Background As the most abundant tumor-infiltrating immune cells, tumor-associated macrophages (TAMs) are significant for fostering tumor progression. CD68 + TAMs display diversely polarized programs comprising CD11c + proinflammatory macrophages (M1) and CD206 + immunosuppressive macrophages (M2). The aim of this study was to determine the survival impact of diametrically polarized TAMs in clear-cell renal cell carcinoma (ccRCC) and their application to stratification of patients according to their prognostic values. Methods The study included 185 consecutive patients with ccRCC who underwent nephrectomy between 1999 and 2001. CD68 + total and diametrically polarized (CD11c + M1 and CD206 + M2) TAM densities were assessed by immunohistochemistry, and the relationships with clinicopathologic features and prognosis were evaluated. Results Low CD11c + TAM density and high CD206 + TAM density were associated with reduced cancer-specific survival ( P  = 0.043 and P  = 0.017, respectively), whereas CD68 + TAM density only had borderline prognostic significance ( P  = 0.062). Furthermore, combined analysis of CD11c + and CD206 + TAMs (CD11c/CD206 signature) had a better power to predict patients’ outcome ( P  = 0.010). Together with TNM stage, tumor necrosis, and performance status, CD11c/CD206 signature was an independent prognostic factor ( P  = 0.010). When applied to the University of California Integrated Staging System intermediate-/high-risk group for localized ccRCC, CD11c/CD206 signature could further distinguish patients with dismal prognosis ( P  = 0.004). Conclusions Intratumoral balance of diametrically polarized TAMs is a novel independent predictor for survival in patients with ccRCC. Tipping the balance toward an antitumoral phenotype might be a promising target of postoperative adjuvant therapy.

Global climatic impacts of El Niño are sensitive to details of the surface warming of the equatorial Pacific Ocean, which vary between each El Niño event. The ability to predict the differences in pattern of anomalous ocean temperatures is explored for two prominent types of El Niño, traditional cold tongue events that have maximum surface warming in the eastern Pacific, and warm pool events that have maximum warming in the central Pacific. We assess seasonal predictions of the two types of El Niño using the Australian Bureau of Meteorology coupled ocean‐atmosphere seasonal forecast model. Prediction of the major differences in pattern of anomalous ocean surface temperature between the two types of El Niño is limited to less than 1 season lead time, which is much shorter than for prediction of the occurrence of El Niño but which does have important practical application for prediction of regional climate. Improved understanding of the mechanisms of warm pool events and reduction of systematic model biases of the mean state and the coupled modes of variability in the Pacific warm pool/cold tongue should lead to improved skill for predicting regional climate variability associated with El Niño.

In bone implants, antibacterial biomaterials with nonleaching surfaces are superior to ones based on abrupt release because systemic side effects arising from the latter can be avoided. In this work, a nonleaching antibacterial concept is demonstrated by fabricating 2D nanoflakes in situ on magnesium (Mg). Different from the conventional antibacterial mechanisms that depend on Mg2+ release and pH increase, the nanoflakes exert mechanical tension onto the bacteria membranes to destroy microorganisms on contact and produce intracellular stress via physical interactions, which is also revealed by computational simulations. Moreover, the nanoflake layer decelerates the corrosion process resulting in mitigated Mg2+ release, weaker alkalinity in the vicinity, and less hydrogen evolution, in turn inducing less inflammatory reactions and ensuring the biocompatibility as confirmed by the in vivo study. In this way, bacteria are killed by a mechanical process causing very little side effects. This work provides information and insights pertaining to the design of multifunctional biomaterials. Nanoflakes are fabricated that stretch bacteria on contact with assistance of the zigzag structure on the edge. The mechanical stress imposed on bacteria triggers a series of reactions such as membrane rupture and reactive oxygen species burst leading to bacterial death. Biomaterials with the nonleaching antibacterial ability are very promising in implants and cause little side effects and inflammation in vivo.

El Niño and La Niña, the warm and cold phases of El Niño–Southern Oscillation (ENSO), cause significant year-to-year disruptions in global climate, including in the atmosphere, oceans, and cryosphere. Australia is one of the countries where its climate, including droughts and flooding rains, is highly sensitive to the temporal and spatial variations of ENSO. The dramatic impacts of ENSO on the environment, society, health, and economies worldwide make the application of reliable ENSO predictions a powerful way to manage risks and resources. An improved understanding of ENSO dynamics in a changing climate has the potential to lead to more accurate and reliable ENSO predictions by facilitating improved forecast systems. This motivated an Australian national workshop on ENSO dynamics and prediction that was held in Sydney, Australia, in November 2017. This workshop followed the aftermath of the 2015/16 extreme El Niño, which exhibited different characteristics to previous extreme El Niños and whose early evolution since 2014 was challenging to predict. This essay summarizes the collective workshop perspective on recent progress and challenges in understanding ENSO dynamics and predictability and improving forecast systems. While this essay discusses key issues from an Australian perspective, many of the same issues are important for other ENSO-affected countries and for the international ENSO research community.