bluuebunny/crossref_metadata_2025 huggingface dataset:
Snoring, daytime sleepiness and stroke: a case–control study of first‐ever stroke
Authors: Davies D. P. , Rodgers H. , Walshaw D. , James O. F. W. , Gibson G. J.
Published: October 2010

Previous reports have shown an association between snoring and stroke but it is not clear whether this reflects confounding factors nor whether the association is attributable to obstructive sleep apnoea (OSA). We performed a case–control study of 181 patients admitted to hospital with first‐ever stroke and community control subjects matched individually for age, sex and general practitioner. Subjects were interviewed with a structured questionnaire to identify snoring, daytime sleepiness and stroke risk factors. The association between snoring alone and stroke was not statistically significant: odds ratio (95% CI) 1.44 (0.88, 2.41). Daytime sleepiness was, however, significantly associated with stroke: odds ratio 3.07 (1.65, 6.08). Multiple logistic regression showed that hypertension, current smoking, taking alcohol regularly (negatively) and a higher Epworth sleepiness score were independently associated with stroke. The results suggest that the previously reported association between ‘simple’ snoring and stroke might have been due to poor controlling for confounding variables. Our study suggests an association with greater sleepiness prestroke, the cause of which is unclear, although OSA is a possible candidate.
The Sleep Disorders Inventory: an instrument for studies of sleep disturbance in persons with Alzheimer's disease
Authors: Tractenberg Rochelle E. , Singer Clifford M. , Cummings Jeffrey L. , Thal Leon J.
Published: October 2010

The Sleep Disorders Inventory (SDI) is an expanded version of one item of the Neuropsychiatric Inventory (NPI). It describes the frequency, severity, and caregiver burden of sleep‐disturbed behaviors during a period prior to its administration. We carried out post hoc analyses on baseline responses to the SDI in 104 persons with Alzheimer's disease (AD) and live‐in caregivers who had been recruited for a trial of melatonin in the treatment of sleep disturbance. These patient‐participants averaged <7 h of sleep per night, measured by actigraph (sleep disturbance), for the 2–3‐week period prior to administration of SDI. Data were from the 2 weeks prior to the baseline visit (SDI, NPI) including actigraph‐derived sleep variables and 2 weeks’ worth of sleep quality ratings (SQR) kept in a diary by caregivers, plus Mini‐Mental State Examination and activities of daily living assessment at baseline. The prevalence of sleep disorder symptoms ranged from 34% (waking up at night thinking it is daytime) and 82% (getting up during the night). Worse SDI scores were associated with worse cognitive, functional, and behavioral status, but not with sex, age, education or duration of dementia. SDI scores were significantly worse in individuals meeting independently established criteria for a diagnosis of ‘sleep disturbance’ (<6 h total sleep time per night) whereas demographic variables and scores reflecting cognition and function were not significantly different across this grouping. The SDI covers a wide range of sleep behaviors and provides information independent of sleep time and SQR.
Nutritional status of pregnant and lactating women in Japan: A comparison with non‐pregnant/non‐lactating controls in the National Nutrition Survey
Authors: Takimoto Hidemi , Yoshiike Nobuo , Katagiri Akane , Ishida Hiromi , Abe Shiro
Published: October 2010

Aim:  To describe the nutritional status in Japanese pregnant and lactating women at a national level, through a comparison with their non‐pregnant/non‐lactating controls.

Material and methods:  Pooled data from five years (1995–1999) of the National Nutrition Survey, Japan. Data on 330 pregnant and 388 lactating women, and their one‐by‐one matched non‐pregnant/non‐lactating controls, were used for analysis.

Results:  There were fewer smokers, drinkers, and exercisers in pregnant women compared to their controls (P < 0.01). Both pregnant and lactating women showed significantly higher intakes of carbohydrates, calcium and vitamin B2. Mean iron intakes ranged 10.3–11.5 mg in the four groups, all being lower than the recommended intake level for non‐pregnant/non‐lactating women (12 mg/day). Pregnant women consumed more fruits, milk and milk products, and less alcohol beverages and fish/shellfish compared to controls. Lactating women consumed more grain, vegetables, milk and milk products, and less alcohol beverages. There were 22.9% anemic subjects (Hb < 11 g/dL) in pregnant women, and 11.1% anemic subjects (Hb < 12 g/dL) in lactating women and 15.7% in non‐pregnant/non‐lactating women. None of the pregnant subjects was severely anemic (Hb < 8 g/dL). No significant differences were observed in iron intakes between anemic and non‐anemic women in each group.

Conclusion:  Pregnant and lactating women in Japan were aware of adopting healthy behaviors, such as smoking less, drinking less, and taking more milk or milk products compared to controls. Prevalence of mild anemia in pregnant women may have been partly due to plasma volume expansion in pregnancy.
Effect of hypoxia on the auditory system of goat fetuses during extrauterine incubation
Authors: Nishioka Nobuko , Nishina Hidenori , Yoshida Koyo , Kinoshita Katsuyuki , Ehara Yoshiro
Published: October 2010

Aim: To investigate the effect of hypoxia on the auditory system in fetuses, we attempted to analyze the auditory brainstem response, the middle latency response, and changes of several physiological parameters of goat fetuses during extrauterine incubation.

Methods: We conducted extrauterine incubation of five goat fetuses at around 127 days of gestation (term = 148 days). Their physiological parameters, such as fetal heart rate, mean blood pressure, flow rate of carotid artery, as well as the auditory brainstem response and middle latency response, were recorded prior to and during hypoxia, and the two sets of data were compared with each other.

Results: In all five cases, the fetal heart rate decreased from 178 ± 12.2 b.p.m. to 144 ± 15.2 b.p.m. during hypoxia, while mean blood pressure and flow rate of carotid artery increased from 37.3 ± 3.7 mmHg to 43.2 ± 5.1 mmHg, and from 38.5 ± 5.5 mL/min to 47.0 ± 5.1 mL/min, respectively. The latency of the auditory brainstem response's wave V and of the middle latency response's Pa wave elongated from 5.24 ± 0.24 ms to 5.69 ± 0.20 ms, and from 19.2 ± 1.6 ms to 20.9 ± 1.4 ms, respectively.

Conclusions: Although fetal compensatory reactions, such as increases in mean blood pressure and flow rate of carotid artery during hypoxia were recognized, elongation of latency, and decrement of amplitude were observed in the auditory brainstem response and middle latency response. These results suggest that hypoxia itself influences the auditory system of the fetus.
Study on the Mechanism of the Bone Formation Process by 17β‐estradiol during Rat Bone Marrow Stromal Cell Culture
Authors: Sado Toshiyuki , Saito Shigeru , Morikawa Hajime
Published: October 2010

The aim of this study is to clarify the mechanism of bone formation by using 17β‐estradiol (E2) during rat bone marrow stromal cell culture. Stromal cells were separated from female rat femora (seven weeks old), and were cultured in an Eagle Minimal Essential Medium (MEM) containing 15% fetal calf serum (FCS). After confluence, the cells were subcultured in a MEM containing 15% FCS (sex steroids removed by charcoal treatment) with dexamethasone, Na betaglycerophosphate and ascorbic acid phosphate for 18 days. They were then cultured in medium containing E2 or insulin‐like growth factor‐I (IGF‐I) alone or with anti‐IGF‐I antibody. On the 14th day, formation of white colored nodules showing positive ALP activity in ALP staining and showing calcium deposition in alizarin red S staining was observed in each culture system, indicating the beginning of calcification. The addition of E2 (10−7M or 10−8M), or IGF‐I (10 and 100 ng/ml) enhanced ALP activity and calcium content significantly, but 17α‐estradiol did not. Anti‐IGF‐I antibody significantly inhibited enhancing effects of E2 and IGF‐I on ALP activity and calcium deposition. Incubating with E2 alone (10–8M), the medium IGF‐I concentration and IGF‐Im RNA expression in the cells were significantly increased on days 10~14, but the expression of IGF‐I receptor mRNA had not changed.

These results suggest that E2 participates in bone formation by promoting IGF‐I production in the bone marrow stromal cells just before calcification starts.

ACTA OBST GYNAEC JPN Vol. 54, No. 10, pp1457–1466, 2002
Determination of sensitivity and specificity of breast tumor diagnosis by primary health care providers (Behvarz) using clinical examination by obstetrician as a gold standard
Authors: Naderi Tayebeh , Bahrampoor Abbas
Published: October 2010

Aim:  The aim of this study was to find a practical screening strategy to detect breast tumors in those who cannot refer to specialists due to problems, such as geographic location, and economical obstacles.

Methods:  Considering the mentioned aim this study was designed to compare the sensitivity and specificity of diagnosis of breast tumors made by health care providers (Behvarz) with those made by specialists. For this, the results of examinations of Behvarzes and an obstetrician on 2000 women referring to the 17 health care centers of Kerman and Zarand cities were compared.

Results:  Among the 2000 women examined by Behvarzes 170 cases were reported to have pathological signs (palpable mass) and 1830 cases were reported without any pathological sign. Among 169 cases diagnosed by physicians as having pathological signs, 162 cases had also been diagnosed by Behvarzes, and there were only seven cases diagnosed by physicians that had been missed by Behvarzes. There were eight cases diagnosed by Behvarzes as having pathological signs that were reported healthy by physicians.

Conclusions:  Based on these findings, the sensitivity and specificity of diagnosis of breast tumors made by Behvarzes was 95.8% and 99.56%, respectively, compared with those made by specialists. Considering the obtained results, the screening program for breast tumors by Behvarzes can be very helpful in early diagnosis of breast tumors.
A randomized controlled study of three targets of propofol plasma concentration in patients undergoing uterine dilation and curettage
Authors: Uerpairojkit Ketchada , Urusopone Pakorn , Somboonviboon Wanna
Published: October 2010

Aim:  To compare the efficacy and the complications of three target levels of propofol plasma concentration in patients undergoing uterine dilation and curettage.

Methods:  Sixty‐nine patients were randomly allocated to receive propofol target controlled infusion at different target concentrations of 4 (group I), 5 (group II) and 6 (group III) mcg/mL combined with 1 µg/kg of fentanyl and 66% of nitrous oxide. Patients’ movement during the procedure, hemodynamic variables, oxygen saturation, end tidal carbon dioxide, time to sleep and awake, and bispectral index score were recorded.

Results:  Seven patients in group I, one in group II, and none in group III (P < 0.05) moved grossly during the procedure. More patients in group III developed hypotension (5 vs 0 and 2 in group I and II, P < 0.05), but no difference was found regarding respiratory complication. No difference was found in time to sleep, but time to wake was longer in group III.

Conclusion:  Propofol infusion at the target concentration of 5 µg/mL was recommended for uterine dilation and curettage when it was administered with fentanyl 1 µg/kg and nitrous oxide 66% under close monitoring and appropriate respiratory management.
Use of fetal‐pelvic index in the prediction of vaginal birth following previous cesarean section
Authors: Wong Kin Sun , Wong Alice Y.K. , Tse Lowina H.Y. , Tang Lawrence C.H.
Published: October 2010

Aim:  To clarify the usefulness of the fetal‐pelvic index as a predictor of vaginal birth after previous lower segment cesarean section.

Methods:  One hundred and seventy women with one lower segment cesarean section who attempted for trial of vaginal birth were enrolled. Pelvimetry was performed to measure maternal pelvic inlet and mid‐cavity circumferences at 37 weeks gestation. Ultrasound was performed to measure fetal head and abdominal circumferences at 38–39 weeks. The fetal‐pelvic index was derived. The predictability of fetal‐pelvic index in the predicting the outcome of delivery was calculated.

Results:  Fifty‐seven (33.5%) women required repeated cesarean section and 113 (66.5%) delivered vaginally. Twenty‐two women with positive fetal‐pelvic index had repeated cesarean section. The predictability of positive fetal‐pelvic index was 48.9%. Ninety of the 125 patients with a negative fetal‐pelvic index delivered vaginally. The predictability of negative fetal‐pelvic index was 72.0%.

Conclusions:  Fetal‐pelvic index derived in the antenatal period has low predictive value in predicting of successful vaginal birth after cesarean section. This index is not useful in clinical practice.
Patients' experiences of laparoscopic cholecystectomy in day surgery
Authors: Barthelsson Cajsa , Lützén Kim , Anderberg Bo , Nordström Gun
Published: October 2010

• Previous research has concentrated mainly on surgical aspects and postoperative complication rates after day surgery laparoscopic cholecystectomy (LC), and less on patients' experiences and nursing care aspects.

• A qualitative study was conducted aimed at investigating patients' experiences of LC in day surgery.

• Ten women and two men were interviewed. The material was coded, categorized and analysed using qualitative analysis.

• The findings demonstrate that individuals with gallstone disease experience limitations in their daily life and feelings of socially handicapped. Prior to surgery, the patients felt anxious and expressed a wish for tranquilizers, and to meet the surgeon responsible.

• At discharge after day surgery, amnesia was experienced and the respondents did not remember important information about the operation given by the surgeon.

• Experience of postoperative pain varied greatly. Several respondents had a relapse of pain on the third day lasting up to 1 week. The need for additional pain medication and a bloated feeling were reported. Some respondents reported nausea and vomiting, and most had questions about wound care.

• The need for additional telephone follow‐up was mentioned, as was the fact that it was difficult to come home to small children. However, the great majority felt that returning home on the same day as the operation, was positive.
The experience of fatigue for people living with hepatitis C
Authors: Glacken Michèle , Coates Vivien , Kernohan George , Hegarty John
Published: October 2010

• Hepatitis C affects approximately 3% of the world population, with fatigue being acknowledged as the cardinal symptom. Despite growing recognition that hepatitis C fatigue impacts in a negative manner on quality of life, at the time of this study no empirical information existed regarding the nature of this fatigue or the way in which it affects a person's life. Such information is needed to enable nurses to engage in appropriate sensitive symptom management which is the core nursing activity with this population, as to date there is no vaccine or widely effective pharmacological therapy.

• The aim of the study was to ascertain the nature of hepatitis C fatigue.

• A qualitative approach using a grounded theory approach was employed. Theoretical sampling generated 28 participants for in‐depth interview. Data analysis consisted of three coding processes, each type of coding having its own purpose and method. Ethical approval was obtained, both from the principal author's academic institution and the participating health care institution.

• Hepatitis C fatigue emerged as being multidimensional in nature, with both acute and chronic versions existing.

• The hepatology community is beginning to acknowledge the significant prevalence of hepatitis C fatigue. This study provides a valuable insight into its nature. This information can serve as resource for practitioners in their development of interventions to enable the hepatitis C virus population live with fatigue in a proactive manner.
Prerequisites and consequences of nursing documentation in patient records as perceived by a group of Registered Nurses
Authors: Björvell Catrin , Wredling Regina , Thorell‐Ekstrand Ingrid
Published: October 2010

• The issue of nursing documentation and care planning has been discussed in numerous articles, revealing barriers and few facilitators in nursing practice. Few of these articles are scientifically researched and they are often based on small samples.

• This study aimed to illuminate the factors that Registered Nurses (RNs) in acute care perceived as prerequisites and consequences relevant to their documentation of nursing care when using the VIPS model (VIPS is an acronym formed from the Swedish words for Well‐being, Integrity, Prevention and Security).

• In total 377 RNs divided into two groups (Groups A and B) completed a questionnaire concerning opinions about nursing documentation. Both groups had received a 3‐day course on nursing documentation based on the VIPS model. Group A had also participated in a 2‐year comprehensive intervention programme.

• The findings showed that most participants, regardless of group, perceived nursing documentation to be beneficial to them in their daily practice and to increase patient safety, and that use of the VIPS model facilitated documentation of nursing care.

• The inhibitors, facilitators and consequences of nursing documentation identified here should help both RNs in practice and their leaders to be more attentive to the prerequisites needed to achieve satisfactory nursing documentation in patient records.
Nurses' personalities, nursing‐related qualities and work satisfaction: a 10‐year perspective
Authors: Sand Åsa
Published: October 2010

• The personalities and qualities of nursing personnel are considered to be of great importance for their interactions and nursing relationships with patients and may also influence work satisfaction.

• The aim of the study was to explore the extent to which different personal qualities and personality factors, with a possible effect on motivation, professional conduct and coping with stress and anxiety, are represented in a group of assistant nurses (second level nurses), and how these qualities are related to nursing competence and long‐range work satisfaction.

• A group of 51 female nursing students (mean age 31.8 years) participated in the study.

• The nursing‐related qualities were empathy, sensitivity to non‐verbal communication, feelings of discomfort in different nursing situations and work satisfaction. The personality factors were psychogenic needs and defence mechanisms.

• At a follow‐up 2 years later, 43 nurses were interviewed, work satisfaction was assessed and nursing competence was appraised. At a follow‐up 10 years after completion of nursing school, 33 of the nurses took part in a telephone interview. Work satisfaction was assessed in 23 of those who were still working as nurses.

• Cluster analysis performed on baseline data resulted in four groups: empathic, discomfort prone, service‐minded and dominant. At the first follow‐up, the service‐minded had the greatest work satisfaction, with many considered to be ‘real jewels’. At the second follow‐up 8 years later, there appeared to be an overrepresentation of injuries and long‐term sick leave in this group, whose members had apparent difficulties in being dominant and asserting own interests. Work satisfaction diminished in all the groups over time. Long‐term work satisfaction was found, however, to be related to degree of empathy and a low degree of sensitivity to aggressiveness.
Views of job satisfaction and dissatisfaction in Australian long‐term care
Authors: Moyle Wendy , Skinner Jan , Rowe Gillian , Gork Chris
Published: October 2010

• The existing job satisfaction literature has tended towards an overemphasis on job satisfaction instruments.

• In the study reported here the views of 27 nurses and assistants‐in‐nursing, collected through focus group interviews, were examined to determine the factors that contribute to workplace satisfaction and dissatisfaction in long‐term care of older people.

• Content analysis of focus group interview data revealed that job satisfaction was related to workplace flexibility, residents, working within a team environment and dedication to the service of optimal resident care. Dissatisfaction was linked to working with unskilled or inappropriately trained staff, laborious tasks such as documentation, staffing levels, tensions within role expectations and the increasing need to be available for overtime.

• In spite of different role expectations, long‐term nursing home care is reported to be a very satisfying area in which to work. However, care managers need to put in place strategies for building improved job satisfaction and workplace incentives to encourage graduates to consider long‐term care opportunities.

• Limitations of the study include the small number of participants, bias towards one organization and lack of generalizability of the results.

• However, the findings confirm many earlier job satisfaction studies and further support the need to consider these issues in relation to recruitment and retention in long‐term care.
Acute Pain Teams in England: current provision and their role in postoperative pain management
Authors: Mcdonnell Ann , Nicholl Jon , Read Susan M.
Published: October 2010

• This survey describes the current provision of multidisciplinary Acute Pain Teams (APTs) in acute English hospitals performing adult in‐patient surgery (excluding maternity). Associations between the presence of an APT and a number of organizational and clinical initiatives for the management of postoperative pain are also explored.

• Postal questionnaires were sent to the Clinical Director of Anaesthetics or head of the APT at every acute English hospital providing separate anaesthetic services.

• After written and telephone reminders, the response rate was 86% (n = 226).

• Eighty‐four per cent (n = 190) of respondents had an APT in their hospital. The presence of an APT was associated (P≤0.05) with higher estimates of patient controlled analgesia and epidural use, regular in‐service training for nurses and junior doctors, written guidelines/protocols for management of postoperative pain, routine use of postoperative pain measurement systems and audit/research in relation to postoperative pain issues.

• Acute Pain Teams, in which nurses play a major role, have a pivotal influence not only in relation to postoperative analgesia but also in wider service development. Since 1995, the number of hospitals offering in‐patient surgery that are covered by an APT has risen. However, despite repeated endorsements from professional bodies, some acute hospitals still have no APT and recent evidence indicates that some APTs face financial problems and provide a ‘token’ service only. Recent policy recommendations may have little impact on the current situation.
The Attending Nurse Caring Model ®: integrating theory, evidence and advanced caring–healing therapeutics for transforming professional practice
Authors: Watson Jean , Foster Roxie
Published: October 2010

• This paper presents a proposed model: The Attending Nursing Caring Model® (ANCM) as an exemplar for advancing and transforming nursing practice within a reflective, theoretical and evidence‐based context.

• Watson's theory of human caring is used as a guide for integrating theory, evidence and advanced therapeutics in the area of children's pain.

• The ANCM is offered as a programme for renewing the profession and its professional practices of caring–healing arts and science, during an era of decline, shortages, and crises in care, safety, and hospital and health reform.

• The ANCM elevates contemporary nursing's caring values, relationships, therapeutics and responsibilities to a higher/deeper order of caring science and professionalism, intersecting with other professions, while sustaining the finest of its heritage and traditions of healing.
Patterns of nursing: a review of nursing in a large metropolitan hospital
Authors: Fitzgerald Mary , Pearson Alan , Walsh Ken , Long Leslye , Heinrich Naomi
Published: October 2010

• In this Clinical Practice Development (CPD) project we set out to identify and describe current approaches to the management and delivery of nursing care in an Australian Metropolitan Teaching Hospital.

• Using a simple descriptive design, data were collected to elicit patterns of care provided by nursing teams. We sought to demonstrate patterns described by nursing teams (interviews) and actual patterns of care (observation).

• As expected there was a degree of incongruence between the espoused and actual patterns of care.

• Interview data revealed that most study wards had a view of nursing that emphasizes meeting the total care needs of patients and their families through offering biopsychosocial and educative care. The observational data revealed that a relatively large proportion of time was expended on activities that were not regarded as important by staff when interviewed (e.g. documentation) while relatively small amounts of time were observed to be spent educating patients or communicating with relatives of patients.

• The identification of this type of gap creates a dissonance in clinicians that can be used to stimulate change through CPD.

• Clinicians used the information to stimulate discussion and to rewrite team value statements.
Ultrastructure and composition of the cell surfaces of infection structures formed by the fungal plant pathogen Colletotrichum lindemuthianum
Authors: O'CONNELL R. J. , PAIN N. A. , HUTCHISON K. A. , JONES G. L. , GREEN J. R.
Published: October 2010

A variety of microscopical techniques and molecular probes have been used to study the ultrastructure and composition of the cell surfaces of the conidia (i.e. spores) and infection structures produced by the hemibiotrophic fungal plant pathogen Colletotrichum lindemuthianum. The fungal conidium germinates to produce a germ‐tube, the tip of which swells to produce a domed, melanized appressorium which adheres firmly to the plant surface. Penetration of the cuticle and cell wall is followed by the development of a biotrophic intracellular hypha, which is surrounded by an invagination of the host plasma membrane. Freeze‐substitution of C. lindemuthianum germlings showed that conidia are coated with a dense layer of fibrillar material. This ‘spore coat’ contains irregularly shaped pores, giving it a reticular appearance. Negative staining of germlings revealed the presence of numerous long, flexuous fibres or fimbriae, protruding from the surfaces of germ‐tubes and appressoria. Colloidal gold was used to visualize fungal extracellular proteins. The colloidal gold stained a fibrillar sheath around germ‐tubes, whereas appressoria were surrounded by a halo, comprising an inner unstained region and a stained perimeter. The carbohydrate composition of the cell surfaces of the conidia and infection structures was studied by labelling cells with rhodamine‐ and fluorescein‐conjugated lectins. The results showed that the extracellular matrices of germ‐tubes and appressoria are very similar in composition, but differ from those of conidia and intracellular hyphae. Monoclonal antibodies have been prepared to germlings and infection structures of C. lindemuthianum and their use has provided further evidence that the extracellular matrices around germ‐tubes and appressoria have several glycoproteins in common. The results also show that the cell surface of C. lindemuthianum becomes specialized during biotrophic development inside host cells.
Development of the gametophyte of the fern Schizaea pusilla
Authors: KISS J. Z. , SWATZELL L. J.
Published: October 2010

Schizaea pusilla is a pteridophyte with several unique developmental characteristics. In contrast to most other fern species, S. pusilla gametophytes remain filamentous throughout their development, and the gametophytes are associated with an endophytic fungus which appears to be mycorrhizal. In terms of tropistic responses, apical filament cells of young gametophytes are negatively phototropic compared with germ filaments of other ferns which exhibit positive phototropism. Cryofixation (propane jet freezing and high‐pressure freezing) in conjunction with freeze substitution electron microscopy was used to study young gametophytes. The results demonstrate that apical filament cells have a distinctive structural polarity and that rhizoids also can be successfully frozen by these methods. The cytoskeleton and endomembrane system were particularly well preserved in cryofixed cells. In addition, Schizaea gametophytes were used as a test system to evaluate potential artifacts of propane jet freezing and high pressure freezing. There was little apparent difference in ultrastructure between cells cryofixed by either freezing method. These gametophytes will be useful in determining the effectiveness of cryofixation techniques and as a model system in tip growth studies.
Immunolocalization of tubulin and actin in thick‐sectioned fungal hyphae after freeze‐substitution fixation and methacrylate de‐embedment
Authors: CZYMMEK K. J. , BOURETT T. M. , HOWARD R. J.
Published: October 2010

Immunolocalizations in whole mounts of walled cells require an empirically derived, species‐specific permeabilization strategy. Particularly when cell walls are recalcitrant to enzymatic digestion, as with many fungi, permeabilization can degrade structure and reduce or destroy antigenicity. To avoid these potential problems, hyphae were freeze‐substituted, embedded in a methacrylate resin, thick‐sectioned and de‐embedded prior to immunolocalization. The cytoskeletal proteins actin and β‐tubulin were labelled via indirect immunofluorescence in hyphal tip cells of Magnaporthe grisea, and Trichoderma viride. Well‐defined punctate actin plaques were observed concentrated at the subapical cell periphery in both species, especially near the hypha–substratum interface. In addition, a Spitzenkörper core and less intense cytoplasmic binding were observed. Immunoelectron microscopy confirmed localization of actin in the Spitzenkörper core and filasomes. β‐Tubulin was immunolocalized as both linear arrays and punctate dots via epifluorescence microscopy. Analysis of 450–550‐nm‐thick serial sections contributed to improved resolution by the reduction of out‐of‐focus blur. Overall, the freeze substitution methacrylate de‐embedment technique provided superior preservation, serial section analysis, and improved antibody penetration and resolution of these cytoskeletal proteins. The technique will be a valuable tool for use with a variety of reporter molecules in cells of fungi.
Brefeldin A effects in plant and fungal cells: something new about vesicle trafficking?
Authors: SATIAT‐JEUNEMAITRE B. , COLE L. , BOURETT T. , HOWARD R. , HAWES C.
Published: October 2010

Whilst the function and organization of the secretory machinery in eukaryotic cells exhibit basic similarities, the compartmentation of the endomembrane system can show significant differences between the fungal, plant and animal kingdoms. The use of the antibiotic brefeldin A (BFA) as an inhibitor of secretion in both animal and yeast cells has resulted in a remarkable advance in our understanding of the modes of action of vesicle shuttles between the endoplasmic reticulum and Golgi apparatus and within the Golgi apparatus itself. It is now apparent that application of the drug to filamentous fungi and plants will also help unravel the workings of the secretory system in these organisms. In this paper we review recent progress in our laboratories on elucidating the effects of BFA on the morphology of the Golgi apparatus and compare these with recently published data on fungal and plant cells. Variation in the response to BFA are reported, which may not all be attributed to differences in drug concentration and time of treatment. These may reflect differences in cellular sensitivity or multiple sites of action of the drug, and the existence of a specific molecular target for BFA is questioned.
A method for the location of specific points on surfaces in the SEM
Authors: CRAWFORD B.
Published: October 2010

A method for precisely locating points on large surfaces during SEM examination and for finding corresponding points on matching surfaces (such as those resulting from the fracture of a solid body) is described. This method also allows for the repeated examination of specific points during subsequent SEM sessions after the specimen has been removed and replaced in the SEM. The method is based on a coordinate transformation between the SEM stage coordinates and specimen coordinate systems defined by arbitrarily chosen reference points on the specimen.
SHORT TECHNICAL NOTE
Authors: NELSON W. G. , WOODS J. L.
Published: October 2010

This paper describes a convenient method for mounting fibres for processing and embedding. Prior to processing, the fibres are mounted across windows in acetate frames. These frames protect the fibres from impact damage during processing, keep the fibres straight, and make alignment of the fibres for sectioning simple and accurate. The frames are produced using purpose‐built devices which are also described in this paper.
Measurement of soft X‐ray absorption spectra and elemental analysis in local regions of mammalian cells using an electronic zooming tube
Authors: ITO A , SHINOHARA K , NAKANO H , MATSUMURA T , KINOSHITA K
Published: October 2010

Direct measurement of absorption spectra for minute areas (2 μm ×2 μm) in a dried mammalian cell was attempted using X‐ray contact images of a whole cell. The wavelength region used ranged from 1.5 to 10 nm covering the absorption edges of the major cellular elements. The measurements were achieved taking advantage of synchrotron radiation as a tuneable light source and an electronic zooming tube as an X‐ray detector with a high spatial resolution. The spectra in every intracellular area exhibited marked absorption changes at the absorption edges of carbon, nitrogen and oxygen, while minor but significant changes for iron and calcium were observed, particularly in the cytoplasmic areas. These results reveal the different spatial distributions of the constituent elements in a cell.
Polystyrene spheres on mica substrates: AFM calibration, tip parameters and scan artefacts
Authors: VAN CLEEF M. , HOLT S. A. , WATSON G. S. , MYHRA S.
Published: October 2010

Atomic force microscopy (AFM), in various versions, has had major impact as a surface structural and spectroscopic tool since its invention in 1986. At its present state of development, however, the interpretation of AFM images is limited by the current state of methodologies for calibration over the wide dynamic range of magnification. Also, the parameters of individual tips, as well as the generic characteristics of different kinds of tips, affect both the quality of the images and their interpretation. Finally, the very nature of the tip‐to‐surface interaction will generate artefacts, in addition to those associated with tip shape, which need to be fully understood by the practitioners of force microscopy. This project seeks to address and shed light on some of these issues.

Polystyrene beads deposited on mica substrates form hexagonal close‐packed layers. The unit cell parameters are suitable for calibration of the AFM in the lateral plane, while the perpendicular spacing of the layers is appropriate for calibration along the vertical axis. Using different size fractions, it is straightforward to determine the extents of linearity, orthogonality, thermal and instrumental drifts over distances from 100 nm to tens of micrometres. The present results show that the methodologies for contact mode operation can be adapted to noncontact modes.

It is known that an AFM image arises from a convolution of surface topography and tip shape, and is mediated by the interaction. In principle it is possible to carry out a deconvolution, if we have complete knowledge about two of the three elements (i.e. tip, surface and interaction). In practice we rarely have the requisite information. Prominent artefacts will occur when the characteristic parameters of the tip are comparable to those of the surface topography, and/or if there is a variable strength, or extent of localization, of the interaction. The present results demonstrate artefacts due to effects of geometry as well as interaction.
Characterization of planar local arrangement by means of the Delaunay neighbourhood
Authors: Bertram M. , Wendrock H.
Published: October 2010

A suitable procedure is presented to characterize the neighbourhood in disperse micro‐structures by measuring the Delaunay neighbour distances and neighbour numbers. Results are discussed from simulation experiments with three germ‐grain models, regular arrangements and a seam‐like model. A plot of variation coefficients is suggested to differentiate between various random distributions of particles.
TEM study of chirality in MoS2 nanotubes
Authors: MARGULIS L. , DLUZEWSKI P. , FELDMAN Y. , TENNE R.
Published: October 2010

The dark‐field diffraction contrast of helical nanotubes (NTs) is shown to be asymmetric when an NT is tilted at appropriate angle with respect to the incident electron beam. This phenomenon was used for the chirality determination of multi‐shell NTs observed in MoS2 layered compound. Both kinds of NT — helical and non‐helical — were found. In the case of helical NTs only right‐hand chirality was observed.
Analysis of spherical aberration of a water immersion objective: application to specimens with refractive indices 1.33–1.40
Authors: Wan D.‐S. , Rajadhyaksha M. , Webb R. H.
Published: October 2010

The method of using immersion medium to correct spherical aberration for water immersion objectives when the samples are not water is investigated. Spherical aberration is measured by an interferometer converted from a confocal microscope for samples with different refractive indices. When the proper refractive index of the immersion medium and thickness of cover slip are selected, the measured spherical aberration approaches zero. A theoretical model can be used for prediction of the immersion medium to correct spherical aberration for various samples. Using the thinnest available cover slip (100 μm), the zero spherical aberration condition can be applied to samples with refractive index as high as 1.40. Confocal images in the condition of almost no spherical aberration are included to demonstrate the improvement of axial resolution due to this correction.
Surface plasmon micro‐ and nano‐optics
Authors: Krenn J. R. , Ditlbacher H. , Schider G. , Hohenau A. , Leitner A. , Aussenegg F. R.
Published: October 2010

We report the experimental realization of key elements of a two‐dimensional optics based on surface plasmon polaritons (SPPs). Local SPP sources, Bragg mirrors and beamsplitters were lithographically built from silver nanostructures. The SPP fields were imaged by detecting the fluorescence of molecules that act as local probes of the SPP near‐field intensity.
Near‐field and confocal surface‐enhanced resonance Raman spectroscopy at cryogenic temperatures
Authors: Anger P. , Feltz A. , Berghaus T. , Meixner A. J.
Published: October 2010

For laser spectroscopy at variable temperatures with high spatial resolution a combined scanning near‐field optical and confocal microscope was developed. Rhodamine 6G (R6G) dye molecules dispersed on silver nano‐particles or nano‐clusters were investigated. For optical excitation of the molecules, either an aperture probe or a focused laser spot in confocal arrangement were employed. Raman spectra in the wavenumber range between 300 cm−1 and 3000 cm−1 at room temperatures down to 8.5 K were recorded. Many of the observed Raman lines can be associated with the structure of the adsorbed molecule. Intensity fluctuations in spectral sequences were observed down to 77 K and are indicative of single molecule sensitivity.
Apertureless scanning near‐field optical microscopy for ion exchange channel waveguide characterization
Authors: Blaize S. , Aubert S. , Bruyant A. , Bachelot R. , Lerondel G. , Royer P. , Broquin J.‐E. , Minier V.
Published: October 2010

We report the characterization of an integrated Ag+/Na+ ion exchange waveguide realized in a silicate glass substrate using apertureless scanning near‐field optical microscopy. Our experimental set‐up is based on the combination of a commercial atomic force microscope with an optical confocal detection system. Thanks to this system, the topography and evanescent optical field at the waveguide top surface are mapped simultaneously. Also, the process of apertureless scanning near‐field optical microscopy image formation is analysed. In particular, fringe patterns appearing in the image reveal the intrinsic interferometric nature of the collected signal, due to interference between the field scattered by the tip end and background fields related to guide losses. We give a quantitative interpretation of these fringes. Evanescent intensity mapping on the sample surface allowed us to extract physical waveguide parameters. In particular, it shows an unambiguous multimode beat along the waveguide propagation axis. Furthermore, we show that analysis of this intensity profile reveals back‐reflection effects from the waveguide exit facet. The resulting standing waves pattern allows us to evaluate the eigenmode propagation constants.
Phase separation in polyfluorene – polymethylmethacrylate blends studied using UV near‐field microscopy
Authors: Chappell J. , Lidzey D. G.
Published: October 2010

In this paper we present a near‐field microscopy study of thin films of a phase‐separated blend of the fluorescent conjugated‐polymer poly(9,9‐dioctylfluorene) [PFO] with the non‐fluorescent polymer polymethylmethacrylate [PMMA]. A scanning near‐field optical microscope (NSOM) was used to generate (blue) fluorescence from the PFO following UV excitation at 362 nm. A range of different concentrations of PFO in PMMA were studied ranging from 1 to 50% PFO in PMMA by mass. By studying both the shear force and fluorescence images we were able accurately to determine the distribution of PFO in the PMMA. We found that phase separation occurs over a number of different length‐scales between 5 µm and 250 nm. We show that at PFO concentrations of 1%, the PFO lies on top of the PMMA. At a PFO relative concentration of 50%, the PMMA phase extends through the whole thickness of the film to the underlying substrate. We use such samples to discuss the resolution of NSOM when imaging thick organic films. Furthermore, we confirm that the length‐scales of phase separation can be modified via control over spin‐casting protocols.
Low‐temperature scanning system for near‐ and far‐field optical investigations
Authors: Kazantsev D. V. , Savio C. Dal , Pierz K. , Güttler B. , Danzebrink H.‐U.
Published: October 2010

A combined system for far‐ and near‐field optical spectroscopy consisting of a compact scanning near‐field optical microscope and a dedicated spectrometer was realized. The set‐up allows the optical investigation of samples at temperatures from 10 to 300 K. The sample positioning range is as large as 5 × 5 × 5 mm3 and the spatial resolution is in the range of 1.5 µm in the far‐field optical microscopy mode at low temperatures. In the scanning near‐field optical microscope mode the resolution is defined by the microfabricated cantilever probe, which is placed in the focus of a double‐mirror objective. The tip‐to‐sample distance in the scanning near‐field optical microscope is controlled by a beam deflection system in dynamic scanning force microscopy mode. After a description of the apparatus, scanning force topography images of self‐assembled InAs quantum dots on a GaAs substrate with a density of less than one dot per square micrometre are shown, followed by the first spectroscopic investigations of such a sample. The presented results demonstrate the potential of the system.
Near‐field Raman imaging of morphological and chemical defects in organic crystals with subdiffraction resolution
Authors: Gucciardi P. G. , Trusso S. , Vasi C. , Patanè S. , Allegrini M.
Published: October 2010

In this study we report on the application of an aperture near‐field optical microscope for Raman imaging of organic materials. Spectral analysis and detailed Raman imaging are performed with integration times of 100 ms per point, without the aid of field enhancement effects. The studied samples consist of two high Raman‐efficiency molecular samples: a 7,7′,8,8′‐tetracyanoquinodimethane crystal showing surface defects and a 7,7′,8,8′‐tetracyanoquinodimethane thin film characterized by the presence of submicrometre‐sized organometallic copper–salt complexes. In the first case, the effect of the surface deformation was studied, whereas in the second sample we were able to chemically image the formation of salt complexes. Subdiffraction resolution was achieved in both studies.
Nano‐patterning photosensitive polymers using local field enhancement at the end of apertureless SNOM tips
Authors: H’dhili F. , Bachelot R. , Rumyantseva A. , Lerondel G. , Royer P.
Published: October 2010

We show experimentally that local optical field enhancement can occur at the end of an apertureless SNOM tip illuminated by an external light source. Our approach consists in the use of a photosensitive polymer, placed in the tip near‐field, to record intensity distribution in the vicinity of the tip end. The excited nanometre‐size light source permits us to produce nano‐patterns on the polymer surface which are then characterized by atomic force microscopy. Experimental images show the influence, on the field enhancement, of three important experimental parameters: the polarization state of the incident light, the geometry of the external illumination and the radius of curvature of the tip apex. These results are shown to be in good agreement with two‐dimensional numerical calculations based on the finite‐difference time‐domain method. We show preliminary nanometre‐size patterns created by this nano‐source excited at a metallic tip extremity and discuss the potential of this approach for near‐field optical lithography.
Demonstrating nanophotonic switching using near‐field pump–probe photoluminescence spectroscopy of CuCl quantum cubes
Authors: Kawazoe T. , Kobayashi K. , Sangu S. , Ohtsu M.
Published: October 2010

We demonstrated a novel optical switching operation using three CuCl quantum cubes with a size ratio of . Their quantized excitonic energy levels resonate with one another, and the switching mechanism was based on the resonant near‐field energy transfer between the quantum cubes. Using near‐field pump–probe photoluminescence spectroscopy, we succeeded in controlling the near‐field energy transfer and obtained a controlled (i.e. switched) signal in a differential photoluminescence spectrum with and without a pump beam. The internal quantum efficiency of the switching operation was close to 1. These results suggest the possibility of making a nanophotonic switching device smaller than 30 nm.