Uncertainty and Irreproducibility of Triboelectricity Based on Interface Mechanochemistry

Triboelectrification mechanism is still not understood, despite centuries of investigations. Here, we propose a model showing that mechanochemistry is key to elucidate triboelectrification fundamental properties. Studying contact between gold and silicate glasses, we observe that the experimental triboelectric output is subject to large variations and polarity inversions. First principles analysis shows that electronic transfer is activated by mechanochemistry and the tribopolarity is determined by the termination exposed to contact, depending on the material composition, which can result in different charging at the macroscale. The electron transfer mechanism is driven by the interface barrier dynamics, regulated by mechanical forces. The model provides a unified framework to explain several experimental observations, including the systematic variations in the triboelectric output and the mixed positive-negative "mosaic" charging patterns, and paves the way to the theoretical prediction of the triboelectric properties.

Recent Advances in Triboelectric Nanogenerators: From Technological Progress to Commercial Applications

Serious climate changes and energy-related environmental problems are currently critical issues in the world. In order to reduce carbon emissions and save our environment, renewable energy harvesting technologies will serve as a key solution in the near future. Among them, triboelectric nanogenerators (TENGs), which is one of the most promising mechanical energy harvesters by means of contact electrification phenomenon, are explosively developing due to abundant wasting mechanical energy sources and a number of superior advantages in a wide availability and selection of materials, relatively simple device configurations, and low-cost processing. Significant experimental and theoretical efforts have been achieved toward understanding fundamental behaviors and a wide range of demonstrations since its report in 2012. As a result, considerable technological advancement has been exhibited and it advances the timeline of achievement in the proposed roadmap. Now, the technology has reached the stage of prototype development with verification of performance beyond the lab scale environment toward its commercialization. In this review, distinguished authors in the world worked together to summarize the state of the art in theory, materials, devices, systems, circuits, and applications in TENG fields. The great research achievements of researchers in this field around the world over the past decade are expected to play a major role in coming to fruition of unexpectedly accelerated technological advances over the next decade.

Distinguishing between primary and secondary volcaniclastic deposits

The distinction between primary and secondary volcaniclastic deposits, which are currently defined as the “direct” products of volcanic eruptions and the “reworked” products of the former, respectively, is the first step to interpreting volcaniclastic deposits, particularly the genetic connection with active volcanism. The distinction appears straightforward, but is not always applicable to natural deposits. During the 3.7 ka BP eruption of the Songaksan tuff ring, Jeju Island, Korea, there was an invasion of typhoon. The tuff ring was partly submerged underwater and affected by wave activity for over a day, resulting in a peculiar volcaniclastic deposit composed of both vent-derived (primary) and substrate-derived (reworked or secondary) volcaniclastic particles. We propose a new term “reprocessed” for a category of volcaniclastic deposits or particles, which originated directly from volcanic eruption but was deposited finally by nonvolcanic processes. Here we show that both reprocessed and reworked particles can coexist in the same volcaniclastic deposit, making it impossible to differentiate it into either a primary or a secondary deposit according to the current definition of volcaniclastic deposits. We thus define the secondary volcaniclastic deposits as comprising either or both of reprocessed and reworked volcaniclastic particles.

Urethral length and bladder neck behavior: can dynamic magnetic resonance imaging give the same results as introital ultrasound?

PURPOSE

To compare dynamic magnetic resonance imaging (dMRI) and introital ultrasound results with regard to urethral length measurements and the evaluation of bladder neck changes.

METHODS

Retrospective analyses of urethral length measurements and detection of bladder neck changes (rotated/vertical bladder neck descent, urethral funneling) were conducted in women-scheduled for surgical treatment with alloplastic material-who had undergone introital ultrasound and dMRI presurgery and 3 months postsurgery. Measurement differences between both imaging modalities were evaluated by assessing the confidence interval for the difference in means between the datasets using bootstrap analysis.

RESULTS

Based on data from 40 patients (320 image series), the urethra could be clearly measured on every pre- and postsurgical dMRI dataset but not on preoperative ultrasound images in nine women during Valsalva maneuver due to a large cystocele. The estimation of the mean difference distribution based on 500,000 bootstrap resamples indicated that the urethral length was measured shorter by dMRI pre- and postsurgery at rest and postsurgery during Valsalva maneuver (median 1.6-3.1 mm) but longer by dMRI (median 0.2 mm) during Valsalva maneuver presurgery. Rotated/vertical bladder neck descent and urethral funneling diagnoses showed concordance of 67-74% in the direct comparison of patients; the estimation of the concordance indicated poorer outcomes with 50-72%.

CONCLUSIONS

Metric information on urethral length from dMRI is comparable to that from introital ultrasound. dMRI is more advantageous in cases with an extended organ prolapse. At present, dMRI does not give the same diagnosis on bladder neck changes as introital ultrasound does.

The impact of a cervical dysplasia diagnosis on individual cancer prevention habits over time: a bicentric case-control study

PURPOSE

Annual cervical cancer screening is recommended in Germany as a part of the statutory preventive care. Abnormal results can provoke psychological distress and anxiety, compromising women's adherence. Little is known about how a cervical dysplasia impacts adherence follow-up visits and prevention habits over time. To optimize care strategies, this study aims to identify women at risk for nonadherence to follow-up visits after a screening event.

METHODS

Between November 2015 and May 2017, participants with an abnormal Pap smear at the Heidelberg and Leipzig University Hospitals received a four-part questionnaire (sociodemographic data, PHQ-D, self-designed fear and prevention habit questions) at the first consultation (T1) and subsequently after 3 (T2) and 6 (T3) months; healthy controls completed the questionnaire at T1.

RESULTS

132 women with an abnormal Pap smear [with conization: S1 (n = 68, 51.5%), without intervention: S2 (n = 64, 48.5%)] and healthy controls (K, n = 101) generally adhered to gynecological checkups, except S1 6 months after the first diagnosis (S1/T3 - 0.47, signed rank p < 0.0005). Knowledge of primary prevention information, i.e., HPV vaccination, was significantly higher among K (K 58%, S1 29%, S2 44%, Chi-squared p = 0.01) as was vaccine uptake (K 39% versus S1/S2 7% and 17%, respectively, Chi-squared p = 0.0004). Fear of upcoming Pap smears rose significantly over time (S1/T1-S1/T2-S1/T3, Wilcoxon signed-rank test p < 0.001) and was higher among those with conization at T2 (Chi-square test, p = 0.01) and partially accompanied by panic disorders at T1 (Chi-square test p = 0.035). Realization of general preventive habits rose significantly among women without an operative procedure (S2) over the study.

CONCLUSION

This study advances the understanding of non-participation in follow-up visits after a dysplasia diagnosis, identifying post-conization women as a special risk group for decreased adherence.

Changes of breast and axillary surgery patterns in patients with primary breast cancer during the past decade

PURPOSE

Breast-conserving therapy (BCT) is the standard procedure for most patients with primary breast cancer (BC). By contrast, axillary management is still under transition to find the right balance between avoiding of morbidity, maintaining oncological safety, and performing a staging procedure. The rising rate of primary systemic therapy creates further challenges for surgical management.

METHODS

Patients with primary, non-metastatic BC treated between 01.01.2003 and 31.12.2016 under guideline-adherent conditions were included in this study. For this prospectively followed cohort, breast and axillary surgery patterns are presented in a time-trend analysis as annual rate data (%) for several subgroups.

RESULTS

Overall, 6700 patients were included in the analysis. While BCT rates remained high (mean 2003-2016: 70.4%), the proportion of axillary lymph node dissection has declined considerably from 80.1% in 2003 to 16.0% in 2016, while the proportion for sentinel lymph node biopsy (SLND) has increased correspondingly from 10.3 to 76.4%. Among patients with cT1-2, cN0 breast cancer receiving BCT with positive SLND, the rate of axillary completion has decreased from 100% in 2008 to 24.4% in 2016.

CONCLUSIONS

In the past decade, SLNB has been established as the standard procedure for axillary staging of clinically node-negative patients. Surgical morbidity has been further reduced by the rapid implementation of new evidence from the ACOSOG Z0011 trial into clinical routine. The results reflect the transition towards more individually tailored, less invasive treatment for selected patient subgroups, especially in regards to axillary lymph node management.

Severe Fournier's gangrene-a conjoint challenge of gynaecology and plastic surgery

Necrotizing fasciitis (NF) is a rare soft tissue infection characterized by rapidly progressing necroses and a high mortality. Prompt diagnosis and immediate medical treatment including radical debridement and broad spectrum antibiotics are the key to successful management. We report on a 46-year-old diabetic female who developed extensive, deep necroses in the perineal area and proximal thighs within a few days. After initial gynaecological consultation, she was transferred directly to our department. Due to the suspicion of NF, an immediate radical debridement was performed. Two more debridements were necessary to control the infection. After stabilization, the extensive soft tissue defect was reconstructed using a combination of plastic reconstructive procedures. Due to early diagnosis, direct referral and immediate surgical treatment, the patient survived.

Pazopanib (GW786034) and cyclophosphamide in patients with platinum-resistant, recurrent, pre-treated ovarian cancer - Results of the PACOVAR-trial

PURPOSE

The prognosis is poor for patients with recurrent, platinum-resistant epithelial ovarian cancer (EOC). Evidence suggests that antiangiogenic treatment modalities could play a major role in EOC. A combined therapy consisting of the investigational oral antiangiogenic agent pazopanib and metronomic oral cyclophosphamide may offer a well-tolerable treatment option to patients with recurrent, previously treated EOC.

PATIENTS AND METHODS

This study was designed as a multicenter phase I trial evaluating the optimal dose as well as activity and tolerability of pazopanib with metronomic cyclophosphamide in the treatment of patients with recurrent, platinum-resistant, previously treated ovarian, peritoneal, or fallopian tube cancer. Here, 50mg cyclophosphamide were combined with 400 to 800mg pazopanib daily.

RESULTS

Sixteen patients were treated; mean age was 66years. At dose levels (DL) I and II, one instance of dose-limiting toxicity (DLT) was seen in one of 6 patients. At DL III, two of four patients showed a DLT, leading to a maximum tolerated dose (MTD) of 600mg pazopanib daily. Median number of administered cycles was 6 (2-13), with three patients being treated for at least 13months. Median progression-free survival (PFS) and overall survival (OS) were 8.35months and 24.95months, respectively. 155 adverse events (AE) occurred, most frequently elevation of liver enzymes, leukopenia, diarrhea and fatigue. Altogether, five serious adverse events (SAE) developed in four patients.

CONCLUSION

Pazopanib 600mg daily p.o. and metronomic cyclophosphamide 50mg daily p.o. is a feasible regimen for patients with recurrent platinum-resistant EOC and showed promising activity in this previously treated patient population.

TRIAL REGISTRATION

Clin.trial.gov registry no.: NCT01238770.

Timing of elective repeat caesarean does matter: Importance of avoiding early-term delivery especially in diabetic patients

Five hundred and three elective repeat caesarean sections were analysed to examine the impact of timing of delivery between 37 and 40 weeks' gestation on foetal and maternal short-term outcome. Gestational age, Apgar scores and admission to the neonatal intensive care unit (NICU)-based foetal outcome. Maternal complications were comparatively evaluated. Due to the increasing incidence of gestational diabetes a subgroup analysis on this issue was performed. Neonates born by elective repeat caesarean in early term had a 3.2 times increased risk of being admitted to the NICU due to foetal adaption disorders in the early post-natal phase. Overall maternal peri-operative risks were low and did not differ significantly between 37 and 41 weeks' gestation. Maternal gestational diabetes constituted an additional independent risk factor in early term. In summary, elective early-term caesarean delivery appears to negatively impact immediate neonatal outcome. Waiting at least until 38 completed weeks' gestation improves foetal outcome, especially in diabetic patients.

Lean Umbilical Cord - a Case Report

The "lean" umbilical cord (also known as thin-cord syndrome) is a comparatively rare anomaly of the umbilical cord, which has seldom been described in the medical literature. We report on a 35-year-old women who presented to us at 29 + 4 weeks gestation with vaginal bleeding and cervical incompetence subsequently complicated not only by premature rupture of membranes but also acute placental insufficiency requiring emergency caesarean section under general anaesthesia at 31 + 2 weeks gestation. At surgery no obvious cause for the acute placental insufficiency - such as placental abruption, cord prolapse or true knot of the umbilical cord - was found. Other possible causes such as vasa praevia or placenta praevia had previously been excluded sonographically on admission for vaginal bleeding. The only notable intraoperative finding was a macroscopically extremely thin umbilical cord.

Changes in chemotherapy usage and outcome of early breast cancer patients in the last decade

Background

During the last decade, neoadjuvant chemotherapy (NACT) of early breast cancer (EBC) evolved from a therapy intended to enable operability to a standard treatment option aiming for increasing cure rates equivalent to adjuvant chemotherapy (ACT). In parallel, improvements in the quality control of breast cancer care have been established in specialized breast care units.

Patients and methods

This study analyzed chemotherapy usage in patients with EBC treated at the Heidelberg University Breast Unit between January 2003 and December 2014.

Results

Overall, 5703 patients were included in the analysis of whom 2222 (39 %) received chemotherapy, 817 (37 %) as NACT, and 1405 (63 %) as ACT. The chemotherapy usage declined from 48 % in 2003 to 34 % in 2014 of the cohort. Further, the proportion of NACT raised from 42 to 65 % irrespective of tumor subtype. In addition, frequency of pathologic complete response (pCR) defined as no tumor residues in breast and axilla (ypT0 ypN0) at surgery following NACT increased from 12 % in 2003 to 35 % in 2014. The greatest effect was observed in HER2+ breast cancer with an increase in patients achieving pCR from 24 to 68 %.

Conclusions

The results mirror the refined indication for chemotherapy in EBC and its preferred usage as NACT in Germany. The increase in pCR rate over time suggests improvement in outcome accomplished by a multidisciplinary decision-making process and stringent measures for quality control.

Electronic supplementary material

The online version of this article (doi:10.1007/s10549-016-4016-4) contains supplementary material, which is available to authorized users.