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BACKGROUND: There are limited data available, particularly in low- and middle-income countries (LMICs), on the long-term quality of life (QoL) and family functioning of primary caregivers of children and young people (CYPs) affected by primary brain tumors (PBTs). This study aimed to assess the factors associated with the mean change in QoL and family functioning scores of primary caregivers of CYP patients with PBTs 12 months posttreatment. METHODS: This prospective cohort study enrolled CYPs aged 5-21 years with newly diagnosed PBTs and their primary caregivers. The study was carried out between November 2020 and July 2023. The primary caregivers of CYPs were recruited from two major tertiary care centers in Karachi, Pakistan. The primary caregivers QoL were assessed by the Pediatric Quality of Life Inventory (PedsQL) Family Impact Module. The assessment was undertaken by a psychologist at the time of diagnosis and 12 months posttreatment. The data were analyzed with STATA version 12. RESULTS: Forty-eight CYPs with newly diagnosed PBTs and their primary caregivers (46 mothers and 2 fathers) were enrolled. At 12 months posttreatment, 25 (52%) CYPs and their primary caregivers (mothers) were reassessed, and 23 (48%) were lost to follow-up. On multivariable analysis, a significant decrease in mothers' mean 12-month posttreatment QoL and family functioning scores was associated with CYP having posttreatment seizures (beta= -10.2; 95% CI: -18.4 to -2.0) and with the financial burden associated with the CYP's illness (beta= -0.3; 95% CI: -0.4 to -0.1). However, in those cases where CYP had higher posttreatment quality of life scores (beta = 0.4; 95% CI = 0.1, 0.6) and posttreatment higher verbal intelligence scores (beta = 0.1; 95% CI = 0.01, 0.3), the mothers' QoL and family functioning scores were significantly greater. CONCLUSION: We found a significant decrease in QoL of mothers who had a high financial burden and whose CYP had posttreatment seizures. However, those whose CYPs had higher posttreatment verbal intelligence scores and quality of life scores had significantly greater QoL scores. Identification of the factors that influence primary caregivers QoL has the potential to aid in the development of targeted strategies to alleviate stressors and improve the overall quality of life for primary caregivers and their children who are at high risk.
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Neoplasias Encefálicas , Cuidadores , Qualidade de Vida , Humanos , Paquistão , Cuidadores/psicologia , Feminino , Criança , Estudos Prospectivos , Masculino , Adolescente , Neoplasias Encefálicas/psicologia , Neoplasias Encefálicas/terapia , Pré-Escolar , Adulto JovemRESUMO
INTRODUCTION: Reliable methods for identifying prematurity and low birth weight (LBW) are crucial to ending preventable deaths in newborns. This study explored healthcare providers' (HCPs) knowledge, practice, perceived barriers in assessing gestational age and birth weight and their referral methods for preterm and LBW infants. The study additionally assessed the potential of using a mobile app for the identification and referral decision of preterm and LBW. METHODS: This qualitative descriptive study was conducted in Thatta District, Sindh, Pakistan. Participants, including doctors, nurses, lady health visitors, and midwives, were purposefully selected from a district headquarter hospital, and private providers in the catchment area of Global Network's Maternal and Newborn Health Registry (MNHR). Interviews were conducted using an interview guide after obtaining written informed consent. Audio recordings of the interviews were transcribed and analyzed using NVIVO® software with an inductive approach. RESULTS: The HCPs had extensive knowledge about antenatal and postnatal methods for assessing gestational age. They expressed a preference for antenatal ultrasound due to the perceived accuracy, though accept practical barriers including workload, machine malfunctions, and cost. Postnatal assessment using the Ballard score was only undertaken sparingly due to insufficient training and subjectivity. All HCPs preferred electronic weighing scales for birth weight Barriers encountered included weighing scale calibration and battery issues. There was variation in the definition of prematurity and LBW, leading to delays in referral. Limited resources, inadequate education, and negative parent past experiences were barriers to referral. Foot length measurements were not currently being used. While mobile apps are felt to have potential, unreliable electricity supply and internet connectivity are barriers. CONCLUSION: The HCPs in this study were knowledgeable in terms of potential tools, but acknowledged the logistical and parental barriers to implementation.
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Doenças do Recém-Nascido , Aplicativos Móveis , Médicos , Lactente , Recém-Nascido , Humanos , Feminino , Gravidez , Peso ao Nascer , Idade Gestacional , Paquistão , Recém-Nascido de Baixo PesoRESUMO
Primary brain tumours (PBTs) are the commonest solid tumours in children and young people (CYP). A study was conducted at a private and a public sector hospital in Karachi, Pakistan, to determine the socio-demographic and tumour-related characteristics of CYP with PBTs between those presenting to the public and private hospitals. A total of 49 patients were included. The commonest PBT was pilocytic astrocytoma (29%). There were no differences in tumour-related characteristics between the two groups. However, parents of CYP with PBTs presenting to the public sector hospital were significantly less educated and had lower household incomes. No significant differences in age, gender, educational status, and ethnicity of CYP with PBTs were observed. Since CYP with PBTs presenting at the public sector hospital were from significantly lower socioeconomic backgrounds and their parents were less educated, it suggests socio-economic disparities in PBT care for CYPs in Karachi, Pakistan.
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Neoplasias Encefálicas , Setor Privado , Criança , Humanos , Adolescente , Centros de Atenção Terciária , Paquistão/epidemiologia , Etnicidade , Neoplasias Encefálicas/epidemiologiaRESUMO
INTRODUCTION: Primary brain tumors are a common cause of morbidity and mortality in children and young people (CYP) globally. Impaired neurocognitive function is a potential severe consequence in primary brain tumor (PBT) survivors. There are no in-depth studies from low- and middle-income countries (LMICs) to inform management and follow-up. The research questions of this study were as follows: Are the sociodemographic factors (lower age of CYP, female gender, low socioeconomic status, low parental education), disease-related factors (high grade of tumor, presence of seizures, presence of hydrocephalous), and treatment-related factors (adjuvant therapy, no surgical intervention, post-treatment seizures, placement of shunts) associated with decline in neurcognition outcomes 12 months post-treatment in CYP with PBTs? METHODS: A prospective cohort study was conducted from November 2020 to July 2023 at the Aga Khan University Hospital and Jinnah Postgraduate Medical Centre, tertiary care hospitals in Karachi, Pakistan. All CYP aged 5 to 21 years with a newly diagnosed PBTs were eligible. The neurocognition assessment was undertaken by a psychologist at two points, i.e., pre-treatment and at 12 months post-treatment using validated tools. The verbal intelligence was assessed by Slosson Intelligence tool, revised 3rd edition (SIT-R3), perceptual reasoning by Raven's Progressive Matrices (RPM), and the Processing Speed Index by Wechsler Intelligence Scale (WISC V) and Wechsler Adult Intelligence Scale (WAIS-IV). The data were analyzed by STATA version 12 software. Generalized estimating equation (GEE) was used to determine the factors associated with the mean change in 12 months post-treatment verbal and non-verbal neurocognition scores. Unadjusted and adjusted beta coefficients with their 95% confidence intervals were reported. RESULTS: A total of 48 CYPs with PBTs were enrolled, 23 (48%) of them were lost to follow-up and 10 (21%) died. The remaining 25 (52%) were reassessed 12 months after treatment. On multivariable analysis, a significant decline in verbal intelligence scores at 12 months was predicted by post-treatment seizures beta = - 20.8 (95% CI, - 38.2, - 3.4), mothers having no formal educational status and lower household monthly income. Similarly, a significant decline in perceptual reasoning scores was also predicted by post-treatment seizures beta = - 10.7 (95% CI, - 20.6, - 0.8), mothers having no formal education and having lower household monthly income. Worsening of processing speed scores at 12 months post-treatment were predicted by tumor histology, post-treatment seizures beta = - 33.9 (95% CI, - 47.7, - 20.0), lower educational status of the mother, and having lower household monthly. However, an improvement was seen in processing speed scores after surgical tumor resection. CONCLUSION: In this novel study, the post-treatment mean change in verbal and non-verbal neurocognition scores was associated with sociodemographic, tumor, and treatment factors. These findings may have potential implications for targeted early psychological screening of higher risk CYP with PBTs. Identification of these predictors may serve as a foundation for developing more cost-effective treatment thereby alleviating the burden of neurocognitive morbidity. However to establish generalizability, future research should prioritize larger-scale, multicountry studies. (Trial registration: ClinicalTrials.gov Identifier: NCT05709522).
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Neoplasias Encefálicas , Centros de Atenção Terciária , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Adulto Jovem , Neoplasias Encefálicas/psicologia , Neoplasias Encefálicas/complicações , Estudos de Coortes , Testes Neuropsicológicos , Paquistão/epidemiologia , Estudos ProspectivosRESUMO
INTRODUCTION: Assessing gestational age accurately is crucial for saving preterm newborns. In low and middle-income countries, such as Pakistan, where access to antenatal ultrasonography (A-USG) is limited, alternative methods are needed. This study evaluated the diagnostic accuracy of foot length (FL) measurement for identifying preterm newborns in rural Pakistan using A-USG as the reference standard. METHODS: A test validation study was conducted between January and June 2023 in rural Sindh, Pakistan, within the catchment area of the Global Network for Maternal Newborn Health Registry, Thatta. Singleton newborns whose mothers had an A-USG before 20 weeks of gestation were enrolled. A research assistant measured FL three times using a rigid transparent plastic ruler within 48 hours of birth and the average FL was reported. Sensitivity, specificity, positive and negative predictive values (PPV, NPV) and likelihood ratios were calculated. The optimal FL cut-off for the identification of preterm newborns was determined using the Youden Index. RESULTS: A total of 336 newborns were included in the final analysis, of whom 75 (22.3%) were born before 37 weeks of gestation. The median gestational age of the newborns was 38.2 weeks, and the median FL was 7.9 cm. The area under the curve was 97.6%. The optimal FL cut-off for identifying preterm newborns was considered as ≤7.6 cm with a sensitivity of 90.8%, specificity of 96.0%, PPV of 86.7% and NPV of 97.3%. A lower cut-off of ≤7.5 cm had a sensitivity of 95.4%, specificity of 84.0%, PPV of 63.1% and NPV of 98.5%. CONCLUSION: In conclusion, this study highlights the utility of FL measurement for identifying preterm newborns in rural settings where A-USG is unavailable before 20 weeks of gestation. Optimal cut-offs of ≤7.6 and ≤7.5 cm provide a simple, cost-effective and reliable tool for clinicians and frontline healthcare providers in rural areas, respectively. TRIAL REGISTRATION NUMBER: NCT05515211.
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Pessoal de Saúde , Saúde do Lactente , Recém-Nascido , Gravidez , Humanos , Feminino , Lactente , Paquistão/epidemiologia , Área Programática de Saúde , Idade GestacionalRESUMO
Background: Brain tumors are a common cause of morbidity, disability, cognitive deterioration and mortality in children, even after treatment. Little is know about the specific causes. The study aimed to assess potential socio-demographic and antenatal factors in primary brain tumor (PBTs) in children and young people (CYP) in Karachi, Pakistan. Designs and methods: A single center hospital based matched case control study in Karachi, Pakistan. Cases were defined as CYP aged between 5 and 21 years with any histological type and grade of primary brain tumor of any histology, stage or grade. Data were collected from parents of 244 patients at the selected center between 2017 and 2021 via telephonic interview. Controls were 5-21 years old CYP admitted with non-oncological diagnoses matched on age and sex. Matched Odds Ratios for predictors of brain tumor in children were derived. Those of statistical significance were included in a multivariable logistic regression model. Results: In the adjusted model, lower paternal education (matched adjusted odds ratio (maOR) 2.46; 95% CI 1.09-5.55), higher household monthly income (maOR 3.4; 95% CI 1.1-10.2), antenatal paternal use of addictive substances (maOR 19.5; 95% CI 2.1-179.8), and antenatal maternal use of analgesics during pregnancy (maOR 3.0; 95% CI 1.2-7.9) were all independently predictive of brain tumors. Conclusion: This matched case-control study found novel associations between maternal use of analgesics, paternal use of addictive substances, higher household income, and lower paternal education and Primary Brain Tumors in Children and Young People. Longitudinal multicenter studies will be required to test these associations prospectively.
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BACKGROUND: Maintaining a good nutritional status during the hematopoietic cell transplantation (HCT) procedure is challenging in the pediatric population. METHODS: In a multicentric retrospective study, we compared the outcome of nutritional status and HCT-related parameters in 227 pediatric patients during and after HCT between 2005 and 2015. 112 patients received a gastrostomy before the start of HCT (GS group), and 115 did not receive a gastrostomy (NGS). Data collection was performed at HCT, 3, 6, and 12 months post-HCT. RESULTS: At time point of HCT the Standard Deviation Score (SDS) of weight was 0.17 in the NGS group, and 0.71 in the GS group (p = .01) Patients in the NGS group lost more weight during the first 3 months after HCT than patients in the GS group. At 12 months, patients in the NGS remained at a lower weight, while patients in the GS group slightly increased their weight. There were no differences between the groups in the incidence of acute graft-versus-host-disease (GvHD), overall survival, and non-relapse mortality. However, the number of febrile episodes requiring intravenous treatment with antibiotics, was higher in the GS group as compared to the NGS group, during the first 3 months post-HCT (p < .001). CONCLUSIONS: Our results indicate that gastrostomy can be utilized in children undergoing HCT without any negative effects on mortality. Therefore, the use of a gastrostomy appears to be a safe option to maintain a good nutritional status during the HCT procedure.
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Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Humanos , Criança , Estudos Retrospectivos , Estudos de Casos e Controles , Gastrostomia , Análise de Sobrevida , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Doença Enxerto-Hospedeiro/etiologia , Condicionamento Pré-Transplante/métodosRESUMO
BACKGROUND: No previous paediatric study has evaluated the frequency of diagnostic disagreement between clinical standard histopathological assessment (CSHA) and retrospective, independent, histopathological assessment (RIHA) of gastrointestinal Graft-Versus-Host Disease (GI-GVHD) METHODS: In a retrospective cohort study, based on gastrointestinal biopsies collected from allogeneic HSCT-treated children (<18 years) with symptom-based GI-GVHD, we evaluated; disagreement of histopathology-based GI-GVHD diagnosis in CSHA vs RIHA, and potential clinical consequences of differences between the assessments. The CSHA-based diagnoses were retrieved from histopathology reports. The RIHA was performed by one pathologist, blinded to the CSHA outcomes and based on the minimal criteria for histopathology-based GI-GVHD diagnosis by the NIH 2014. RESULTS: Seventy children with 92 endoscopic occasions (including 22 re-endoscopies) were enrolled. GI-GVHD was observed in 73% (67/92) of the endoscopies in the RIHA and in 54% (50/92) in the CSHA (P = .014). The RIHA confirmed 94% (47/50) with GI-GVHD and 52% (22/42) with non-GI-GVHD diagnoses, established in the CSHA. Disagreement, that is endoscopic occasions with GI-GVHD solely detected in RIHA or detection of GI-GVHD in CSHA but not in RIHA, was observed in 20/42 (48%) and 3/50 (6%), respectively (McNemar's test, P = .0008). The risk of a subsequent re-endoscopy was higher in endoscopic occasions with GI-GVHD detected in RIHA but not in CSHA vs if non-GI-GVHD were detected in both readings (P = .005). CONCLUSION: Our results suggest that in children with symptom-based GI-GVHD without histopathological confirmation in CSHA, a second, NIH 2014 based histopathological assessment should be considered before performing a re-endoscopy.
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Gastroenteropatias/diagnóstico , Trato Gastrointestinal/patologia , Doença Enxerto-Hospedeiro/diagnóstico , Transplante de Células-Tronco Hematopoéticas , Biópsia , Criança , Diagnóstico Diferencial , Endoscopia Gastrointestinal , Feminino , Gastroenteropatias/imunologia , Doença Enxerto-Hospedeiro/imunologia , Humanos , Masculino , Estudos Retrospectivos , SuéciaRESUMO
Endoscopy with histopathological assessment is an established practice to confirm gastrointestinal graft-versus-host disease (GI-GVHD). However, the clinical relevance of this approach in children is incompletely evaluated. In a retrospective cohort study, we investigated the frequency of treatment changes in response to histopathological findings in all children (<18 years) in Sweden who underwent endoscopy for suspected GI-GVHD (2000-2013) after receiving hematopoietic stem cell transplantation. Sixty-eight children with ninety-one endoscopic occasions were enrolled. At the time of endoscopy, anti-GI-GVHD treatment was ongoing in 71% (65/91). In 18% (12/65) with ongoing treatment, no histopathological evidence of GI-GVHD or another cause to justify anti-GI-GVHD treatment was found. In 48% (44/91), endoscopy with histopathological assessment led to changes in the treatment regimen. Re-endoscopy was more frequent among those with treatment changes, versus unchanged treatment, 39% (17/44) and 13% (6/47), respectively (P = .007). Histopathological findings generating treatment changes were as follows: GI-GVHD in 68% (30/44), normal histology in 25% (11/44), and an alternative diagnosis in 7% (3/44). In conclusion, this study supports that endoscopy with histopathological assessment should be considered in all children with suspected GI-GVHD.
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Gastroenteropatias , Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Criança , Endoscopia , Gastroenteropatias/diagnóstico , Gastroenteropatias/etiologia , Doença Enxerto-Hospedeiro/diagnóstico , Doença Enxerto-Hospedeiro/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Estudos Retrospectivos , SuéciaRESUMO
OBJECTIVES: Gastrointestinal graft-versus-host disease (GI-GVHD) is a potentially life-threatening complication after hematopoietic stem cell transplantation. Symptoms indicating GI-GVHD motivates endoscopy with biopsy sampling and histopathological confirmation. Optimal extent of endoscopy in children is, however, presently unknown. Therefore, we aimed to evaluate whether biopsies from the rectosigmoid area versus the rest of the colon/ileocolon with or without biopsies from simultaneous upper endoscopy, were equally reliable for detection of GI-GVHD and relevant differential diagnoses. METHODS: Retrospective multicenter study based on histopathological re-evaluation of biopsies and hospital record data, collected from children with suspected GI-GVHD. RESULTS: Forty-four children with 51 endoscopic occasions (81 procedures) were included. Thirty-nine of 51 (76.5%) were diagnosed as GI-GVHD, 14 (27.4%) received a differential diagnosis and 7 (13.7%) had normal histology findings. Comorbidity, that is, simultaneous detection of a differential diagnosis and GI-GVHD, was observed in 9 (23.1%) cases. Cytomegalovirus infection was the most frequent differential diagnosis, 6 of 7 were detected in biopsies from rectosigmoid and esophagogastroduodenal areas. Sensitivity for detection of GI-GVHD in biopsies collected from rectosigmoid-ileocolonic-, rectosigmoid-, or esophagogastroduodenal areas were 97.4%, 84.6%, 83.3%, respectively, and 97.4% when the latter 2 were merged. The difference, nondetected GI-GVHD in the rectosigmoid area versus detected elsewhere in the GI tract, was statistically significant (Pâ=â0.03). CONCLUSIONS: Biopsies collected from the rectosigmoid area solely were not optimal for detection of pediatric GI-GVHD. When biopsy sampling from rectosigmoid and upper GI tract areas was combined, the sensitivity for GI-GVHD was, however, equally high as for ileocolonoscopy or full upper and lower endoscopy.
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Biópsia/métodos , Endoscopia Gastrointestinal/métodos , Trato Gastrointestinal/patologia , Doença Enxerto-Hospedeiro/diagnóstico , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Adolescente , Criança , Pré-Escolar , Infecções por Citomegalovirus/diagnóstico , Diagnóstico Diferencial , Feminino , Doença Enxerto-Hospedeiro/patologia , Humanos , Masculino , Estudos Retrospectivos , Sensibilidade e Especificidade , SuéciaRESUMO
INTRODUCTION: C-reactive protein (CRP), white blood cell (WBC) and absolute neutrophil counts (ANC) are important inflammatory biomarkers in the early diagnosis of infections. However, little is known on their profile and usefulness in fever case management in children attending outpatient clinic in rural north-eastern Tanzania. METHODS: Patients aged between 2 and 59 months presenting with fever at Korogwe District Hospital were enrolled. Venous blood was collected for evaluation of serum CRP, WBC and ANC. Individual patient diagnosis was based on integrated management of childhood illness (IMCI) guidelines and laboratory investigations (blood and urine cultures). RESULTS: A total of 867 patients were enrolled, out of which 691 (79.7%) had complete clinical and laboratory data available for analysis. Acute upper respiratory tract infection 284 (41.1%), acute gastroenteritis 127 (18.4%) and pneumonia 100 (14.5%) were the most frequent diagnoses. The geometric mean levels of serum CRP, WBC and ANC were 10.4 (95% CI: 9.2 - 11.8), 11.5 (95% CI: 11.1 - 11.9) and 5.5 (95% CI: 5.2 - 5.8), respectively. CRP≤20, WBC≤15 (103cells/µL) and ANC≤10 103cells/µL) were observed in the majority of the patients with upper respiratory tract infection, pneumonia, acute gastroenteritis and non-specific febrile illness. Only serum CRP levels were positively correlated with positive blood cultures at a calculated cut-off value of 37.3 mg/L, giving a specificity of 77.8% and sensitivity of 74.2%. CONCLUSION: CRP assessment together with IMCI guidelines may be useful in assisting the diagnosis and management of paediatric febrile infections in Tanzania.
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Proteína C-Reativa/metabolismo , Febre/etiologia , Infecções/diagnóstico , Leucócitos/metabolismo , Biomarcadores/metabolismo , Pré-Escolar , Feminino , Febre/diagnóstico , Humanos , Lactente , Infecções/sangue , Contagem de Leucócitos , Masculino , Neutrófilos/metabolismo , Guias de Prática Clínica como Assunto , População Rural , Sensibilidade e Especificidade , TanzâniaAssuntos
Circuncisão Masculina/efeitos adversos , Religião e Medicina , Sociedades Médicas , Comissão de Ética , Humanos , Islamismo , Judaísmo , Masculino , SuéciaAssuntos
Alimentação com Mamadeira/efeitos adversos , Desidratação/etiologia , Hiponatremia/etiologia , Fórmulas Infantis/administração & dosagem , Desidratação/diagnóstico , Desidratação/terapia , Emergências , Rotulagem de Alimentos , Humanos , Hiponatremia/diagnóstico , Hiponatremia/terapia , Lactente , Masculino , Fatores de Risco , Desequilíbrio Hidroeletrolítico/diagnóstico , Desequilíbrio Hidroeletrolítico/etiologia , Desequilíbrio Hidroeletrolítico/terapiaRESUMO
The fabrication of core-shell structures is crucial for many nanowire device concepts. For the proper tailoring of their electronic properties, control of structural parameters such as shape, size, diameter of core and shell, their chemical composition, and information on their strain fields is mandatory. Using synchrotron X-ray diffraction studies and finite element simulations, we determined the chemical composition, dimensions, and strain distribution for series of InAs/InAsP core-shell wires grown on Si(111) with systematically varied growth parameters. In particular we detect initiation of plastic relaxation of these structures with increasing shell thickness and/or increasing phosphorus content. We establish a phase diagram, defining the region of parameters leading to pseudomorphic nanowire growth. This is important to avoid extended defects which are detrimental for their electronic properties.
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We have developed a technique so that both transmission electron microscopy and microphotoluminescence can be performed on the same semiconductor nanowire over a large range of optical power, thus allowing us to directly correlate structural and optical properties of rotationally twinned zinc blende InP nanowires. We have constructed the energy band diagram of the resulting multiquantum well heterostructure and have performed detailed quantum mechanical calculations of the electron and hole wave functions. The excitation power dependent blue-shift of the photoluminescence can be explained in terms of the predicted staggered band alignment of the rotationally twinned zinc blende/wurzite InP heterostructure and of the concomitant diagonal transitions between localized electron and hole states responsible for radiative recombination. The ability of rotational twinning to introduce a heterostructure in a chemically homogeneous nanowire material and alter in a major way its optical properties opens new possibilities for band-structure engineering.
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We demonstrate high-fidelity guidance of axons using rows of nanowires. The axons are prevented from crossing the rows, making it possible to guide and sort a large number of axons as opposed to when chemical patterns are used. Focal adhesion forms at the nanowires establishing a possible site of information transfer between the surface and the cells. Rows of gallium phosphide (GaP) nanowires were epitaxially grown on GaP(111) substrates in patterns defined by electron beam lithography.
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We investigate the surface-enhanced Raman scattering (SERS) of rhodamine 6G (R6G) adsorbed on Au nanoparticles attached to InP nanowires. We find that nanowire arrays act as frameworks for effective SERS substrates with a significantly higher Raman signal sensitivity than a planar framework of Au nanoparticles adsorbed two-dimensionally on a flat surface. The SERS signal displays a clear polarization-dependent effect when the nanowires are arranged in a row. We also find that the SERS signal increases with time during continuous laser illumination. The plasmon-enhanced optical forces between Au nanoparticles may either move pairs of nanoparticles closer together or attract adsorbed molecules by moving them to the junctions of Au nanoparticle aggregates. Such effects by plasmon optical forces may cause the observed increase of the SERS signal with continuous laser illumination.