Photoelectrical properties of graphene/doped GeSn vertical heterostructures

GeSn is a group IV alloy material with a narrow bandgap, making it favorable for applications in sensing and imaging. However, strong surface carrier recombination is a limiting factor. To overcome this, we investigate the broadband photoelectrical properties of graphene integrated with doped GeSn, from the visible to the near infrared. It is found that photo-generated carriers can be separated and transported with a higher efficiency by the introduction of the graphene layer. Considering two contrasting arrangements of graphene on p-type and n-type GeSn films, photocurrents were suppressed in graphene/p-type GeSn heterostructures but enhanced in graphene/n-type GeSn heterostructures when compared with control samples without graphene. Moreover, the enhancement (suppression) factor increases with excitation wavelength but decreases with laser power. An enhancement factor of 4 is achieved for an excitation wavelength of 1064 nm. Compared with previous studies, it is found that our graphene/n-type GeSn based photodetectors provide a much wider photodetection range, from 532 nm to 1832 nm, and maintain comparable responsivity. Our experimental findings highlight the importance of the induced bending profile on the charge separation and provides a way to design high performance broadband photodetectors.

The photoelectrical properties of graphene integrated with doped GeSn have been investigated and a high performance broadband photodetection can be achieved by integration of graphene with n-type GeSn.     

How to optimise urinary continence in anatomical endoscopic enucleation of the prostate?

The traditional transurethral resection of the prostate (TURP) is considered as gold-standard surgical treatment to relieve symptoms resulting from bladder outlet obstruction by prostate enlargement. However, with the advances of novel laser technologies and more experienced surgeon conquering the steep learning curve, anatomical endoscopic enucleation of prostate (AEEP) has become a more popular alternative surgical technique. Although AEEP has compatible functional outcome, less blood loss, shorter catheterisation duration and hospital stay, the risk of post-operative urinary incontinence (UI) is often an issue of concern. In this review, we focus on discussion about risk factors related to increased incidence of UI, some surgical tips to avoid damaging external urinary sphincter and treatment strategies to facilitate recovery of urinary continence after surgery.     

Median nerve fascicle transfer versus ULNAR nerve fascicle transfer to the biceps motor branch in C5‐C6 and C5‐C7 brachial plexus injuries: Nonrandomized prospective study of 23 consecutive patients

The purpose of this study was to observe whether the results of the median nerve fascicle transfer to the biceps are equivalent to the classical ulnar nerve fascicle transfer, in terms of elbow flexion strength and donor nerve morbidity. Twenty‐five consecutive patients were operated between March 2007 and July 2013. The patients were divided into two groups. In Group 1 (n = 8), the patients received an ulnar nerve fascicle transfer to the biceps motor branch. In Group 2 (n = 15), the patients received a median nerve fascicle transfer to the biceps motor branch. Two patients with follow‐up less than six months were excluded. Both groups were similar regarding age (P = 0.070), interval of injury (P = 0.185), and follow‐up period (P = 0.477). Elbow flexion against gravity was achieved in 7 of 8 (87.5%) patients in Group 1, versus 14 of 15 (93.3%) patients in Group 2 (P = 1.000). The level of injury (C5‐C6 or C5‐C7) did not affect anti‐gravity elbow flexion recovery in both the groups (P = 1.000). It was concluded that the median nerve fascicle transfer to the biceps is as good as the ulnar nerve fascicle transfer, even in C5‐C7 injuries. © 2014 Wiley Periodicals, Inc. Microsurgery 34:511–515, 2014.     

Nonlinear permanent migration response to climatic variations but minimal response to disasters

We present a microlevel study to simultaneously investigate the effects of variations in temperature and precipitation along with sudden natural disasters to infer their relative influence on migration that is likely permanent. The study is made possible by the availability of household panel data from Indonesia with an exceptional tracking rate combined with frequent occurrence of natural disasters and significant climatic variations, thus providing a quasi-experiment to examine the influence of environment on migration. Using data on 7,185 households followed over 15 y, we analyze whole-household, province-to-province migration, which allows us to understand the effects of environmental factors on permanent moves that may differ from temporary migration. The results suggest that permanent migration is influenced by climatic variations, whereas episodic disasters tend to have much smaller or no impact on such migration. In particular, temperature has a nonlinear effect on migration such that above 25 °C, a rise in temperature is related to an increase in outmigration, potentially through its impact on economic conditions. We use these results to estimate the impact of projected temperature increases on future permanent migration. Though precipitation also has a similar nonlinear effect on migration, the effect is smaller than that of temperature, underscoring the importance of using an expanded set of climatic factors as predictors of migration. These findings on the minimal influence of natural disasters and precipitation on permanent moves supplement previous findings on the significant role of these variables in promoting temporary migration.Human migration has been identified as a potentially important response to climate change. Where climate change makes habitation in certain places less desirable or even impossible, people may respond by moving elsewhere. However, the idea that environmental change induces people to migrate remains a widely contested topic, especially given recent findings suggesting that environmental changes may also constrain movement (1–3). Historically, there has been a paucity of empirical demonstrations of environmental effects on population mobility, partly due to sparse data and partly because migration studies have tended to focus on further exploration of social and economic predictors of migration that have already been established as primary drivers. More recently however, new empirical approaches to exploring the relationship between migration and climate change have emerged.Based on a review of the existing literature (SI Text, Literature Review), there is conflicting evidence on the effects of climatic variations and natural disasters on migration, partly arising from the inability to distinguish permanent moves from temporary ones, especially in the case of macrolevel studies that analyze aggregate flows of people. Furthermore, the effects may vary significantly by distance of migration destination, which may also confound the overall effect of environmental factors on migration. Above all, most studies at the microlevel do not simultaneously examine the effects of both disasters and climatic changes on migration, and often use only one aspect of climate, generally variation in rainfall. However, precipitation and temperature are historically correlated and to infer an unbiased effect of either one on migration probability, both need to be included in the model (4).The current study therefore attempts to improve on the existing studies. This study is, to our knowledge, the first at a microlevel to simultaneously explore the effects of sudden natural disasters and climatic variations on permanent migration of the whole household. (Household migration can take several forms: migration of a single member or individual migration; migration of one or more members of the household or split household migration; and migration of whole household, which includes migration of the entire household along with the head of household.) In doing so, we test the effect of temperature along with precipitation on migration decision. We include a summary that allows a quick comparison of the methodology used in our study compared with previous studies in terms of the choice of environmental variables to predict migration (Table S1). Prior studies have primarily examined individual migration behavior, which may capture both temporary and permanent migration. In contrast, province-level migration of entire households, as we show (with the use of data that follows households over a period of 15 y), tends to be more permanent. (We hereafter use the term “permanent.”) To our knowledge, the only other studies that focus on household migration explore the mechanisms by which natural disasters can deter migration of the household or its relatives (5, 6). By studying migration behavior of the whole household, we are able to focus on permanent migration, and therefore directly test how sudden disasters along with variations in rainfall and temperature affect permanent and relatively longer distance (province-to-province) migration as opposed to temporary movement; this allows us to complement the findings in some existing studies that generally conclude that natural disasters and rainfall result in temporary and short-distance moves while providing new evidence on the temperature–migration link in the context of microlevel studies.To achieve these goals, we chose Indonesia as our study site because as the world’s largest archipelago situated in a tectonically active location, the country is highly exposed to both geologic and climatic hazards (SI Text, Background on Indonesia). In addition, as the world’s fourth most populous country with ∼40% of the labor force engaged in agriculture and more than 60% of the total population living in the coastal areas, the country is extremely vulnerable to the impacts of climate variations and extreme events (SI Text, Background on Indonesia). At the same time, the availability of household panel data with an exceptional tracking rate allows us to use a difference-in-differences approach to study the migration of households before and after disasters as well as establish a plausibly causal link between climatic variations and migration. We use the Indonesian Family Life Survey (IFLS), a household panel survey representative of ∼83% of the Indonesian population from 13 of the 27 provinces in 1993 (Fig. S1). The IFLS provides data on 7,185 original households, followed over a period of 15 y (Materials and Methods). The migration outcome we predict captures migration of households, which is likely permanent. We track whole-household migration for a 15-y period during which the original households are followed with a very high retention rate even after they migrate. Some 95% of the migrant households end up migrating only once and do not return to their original province during the entire 15-y period. Therefore, at least in the Indonesian case, the provincial level migration of households seems to be permanent (see SI Text, Internal Migration in Indonesia, for more on internal migration in Indonesia).The household panel data are supplemented with data on natural disasters taken from DesInventar database, which provides disaster-related data using information on disasters of different intensities based on preexisting official data, academic records, newspaper sources, and institutional reports. Different types of disasters may not all affect migration in the same way, thus cancelling out each other’s effects on migration. For our analysis, we therefore separately estimate the effects of each type of disaster. Furthermore, we use multiple measures to capture the different ways in which a disaster may affect the population, for three primary reasons. First, we believe that the intensity of disaster rather than simply the occurrence of disaster should more accurately predict its effect. Measures such as number of deaths, number injured, number of houses destroyed, and amount of financial loss (captured by monetary loss measured in Indonesian Rupiah) from each type of disaster aggregated at the province level are used to capture both the frequency as well as the intensity of disasters. Second, relying on a single measure of a disaster may not capture its overall effect because a certain event may result in large financial losses but inflict little physical harm. Third, using alternate measures of disaster allows one to compare and confirm results, and can be used as a robustness check (Materials and Methods).Finally, for measures of climatic variations, we construct estimates of average temperature and precipitation for each province during each observation interval (Materials and Methods), because temperature and rainfall variations together provide a more complete measure of the extent of climate variations that may affect migration (7).     

Long-term functional outcomes of diffuse pigmented villonodular synovitis of knee: The role of adjuvant radiotherapy

Diffuse pigmented villonodular synovitis (PVNS) of knee is a rare benign disease that has a destructive clinical course. Synovectomy and adjuvant radiotherapy (RT) have been reported as treatment options but literatures reporting functional outcomes were sparse. This study aimed to evaluate the long-term functional outcomes and disease control among treatment modalities through the 22 years of experience.A single-center database was searched for patients who received synovectomy of knee with the pathologic diagnosis of PVNS. General data, treatment modalities, and recurrent status were retrospectively collected from medical records. Functional outcomes were evaluated by Western Ontario and McMaster Universities Osteoarthritis Index through phone interviews by an independent orthopedist.From January 1995 to December 2017, 24 patients with diffuse PVNS of knee were identified, including 19 receiving open synovectomy (OP) and 5 undergoing arthroscopic surgery. Adjuvant RT was performed on 14 patients with a median dose of 35 Gy (range 20–40 Gy). After median follow up of 6 years, recurrences were recorded in 10 cases. The recurrence rate was significantly lower in the OP + RT group than the OP group (8.3% vs 57.1%, P = .038). Among those with preserved knee joints, there was no significant difference in the Western Ontario and McMaster Universities Osteoarthritis Index score and stiffness score between patients in the OP + RT and OP groups.For patients with diffuse PVNS of knee, the addition of moderate-dose adjuvant RT following OP provided excellent local control while maintaining good joint function with limited treatment-related morbidity. Our study emphasized the importance of moderate dose RT in diffuse PVNS of knee joint.     

TP53 alterations in relapsed childhood acute lymphoblastic leukemia

TP53 alterations are frequent relapse‐acquired mutations in childhood acute lymphoblastic leukemia (ALL). The present study evaluated the clinical significance of relapsed childhood ALL in Taiwan. Diagnostic and/or relapsed bone marrow or peripheral blood was obtained from 111 children with relapsed ALL who were initially treated by using Taiwan Pediatric Oncology Group (TPOG) ALL protocols from January 1997 to May 2018. Mutations were detected by PCR and sequencing, as well as by multiplex ligation‐dependent probe amplification to detect copy number alterations. Copy number and/or sequence alterations of TP53 were detected in 29% (28 of 98) and in 46% (6 of 13) of patients with relapsed B‐cell and T‐cell ALL, respectively. This incidence was much higher than that in several similar studies conducted in Caucasian populations. Seventy percent of all TP53 alterations were gained at relapse in 67 matched samples by back‐tracking matched diagnostic samples. TP53 alterations were associated with lower 5‐year event‐free survival (EFS) and overall survival (OS) rates (P = .013 and P = .0002, respectively). Multivariate analysis confirmed the prognostic significance of TP53 alterations. Forty‐five patients received hematopoietic stem‐cell transplantations post‐relapse. Patients with TP53 alterations (14/45) had inferior 5‐year EFS and OS than patients without TP53 alterations after transplantation (P = .002 and P = .001, respectively). The significance of these TP53 alterations for patients who received transplantations was confirmed by multivariate analysis. In conclusion, TP53 alterations were enriched and useful as prognostic markers in relapsed childhood ALL.