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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 290: 122299, 2023 Apr 05.
Article in English | MEDLINE | ID: mdl-36608520

ABSTRACT

The rotational line survey by ALMA (Atacama Large Millimeter/submillimeter Array) recently revealed the presence of i-C3H7CN (i-PrCN) and n-C3H7CN (n-PrCN) in 3-mm atmospheric window between 84 to 111 GHz towards the hot core region Sagittarius B2(N) (Sgr B2(N)). This was the first interstellar detection of a linear straight chain molecule. In this light, we report the rotational spectra of C5H12 isomeric group in the same frequency range. We performed quantum chemical calculations for spectroscopic parameters. The pure rotational spectrum of the species has been simulated using the PGOPHER program. The rotational spectrum of this molecule makes it a good candidate for future astronomical detections since the radio lines can be calculated to very high accuracy in mm/sub-mm wave region.

2.
Musculoskelet Surg ; 106(3): 325-335, 2022 Sep.
Article in English | MEDLINE | ID: mdl-33870477

ABSTRACT

BACKGROUND: Little literature exists regarding aggressive treatment of the extrusion in the early stage of the disease and the outcome at skeletal maturity. The purpose of the study was to evaluate the outcome of the disease with onset younger than 7 years, treated in the early stage of the disease, with aggressive management of significant extrusion (immediate containment with fixed abduction brace in children less than 5 years and varus derotation osteotomy in older children), and reached skeletal maturity. METHODS: All children with the age of onset younger than 7 years of disease during active Perthes disease were prospectively followed. Children with early stages of the disease (modified Elizabethtown classification) and reached skeletal maturity were included (68 children). The extrusion of the femur head was calculated by Reimer's migration index on both sides. A migration difference 12 % or above was considered as "significant extrusion". Children without significant extrusion were treated non-operatively; children with significant extrusion were treated with varus derotation osteotomy. The final radiological outcome was assessed by the Stulberg classification and sphericity deviation score (SDS). The independent "t" test and Chi-square test were done to compare the difference between the two groups. RESULTS: The mean age at the onset and the final follow-up was 5.7 years and 15.3 years. The frequency of significant extrusion was 57%. At the final follow-up, an excellent clinical outcome and radiological outcomes (in 88% hips) were noted. There was no significant difference in the Stulberg groups and SDS (sphericity deviation score) in both groups. CONCLUSION: The outcome of the children who had the age of onset of the disease less than 7 years was good with early and aggressive management of the extrusion. The reversal of extrusion is associated with a similar result of non-operative children in this age group. LEVEL OF EVIDENCE: III.


Subject(s)
Legg-Calve-Perthes Disease , Age of Onset , Child , Femur Head/diagnostic imaging , Femur Head/surgery , Follow-Up Studies , Hip Joint/surgery , Humans , Legg-Calve-Perthes Disease/diagnostic imaging , Legg-Calve-Perthes Disease/surgery , Treatment Outcome
3.
Aust Dent J ; 66(3): 270-277, 2021 09.
Article in English | MEDLINE | ID: mdl-33521979

ABSTRACT

OBJECTIVES: To examine if making a visit, number of visits and services varied by predisposing (gender, perceived health competence, education, previous relief of pain visit), enabling (dental anxiety, income, social support) and need (perceived need, number of teeth and oral pain) characteristics. METHODS: Dental visiting and services data from a sample of middle-aged South Australian adults were collected from 61% of participants at 12-months (n = 603) and 59% after 24-months (n = 583). Visiting over 2-years, mean visits and mean services were analysed by log binomial and Poison regression using the Andersen and Newman model. RESULTS: The percentage having a dental visit over 2-years was lower for males than females, prevalence ratio (PR, 95% CI) 0.91 (0.84, 0.99), and for higher than lower dental anxiety, PR = 0.78 (0.62, 0.98). Number of visits was associated with higher than lower income, rate ratio (RR, 95%CI) 1.20 (1.02, 1.41) but lower for those with higher social support, RR = 0.86 (0.74, 0.99). Services were lower for those with higher perceived health competence, RR = 0.72 (0.56, 0.92) but higher for those with perceived needs, RR = 1.22 (1.01, 1.46). CONCLUSIONS: While need and cost factors predict dental service use, psychosocial variables such as health competence and social support also need to be considered.


Subject(s)
Dental Care , Income , Adult , Australia/epidemiology , Disease Susceptibility , Female , Humans , Male , Middle Aged , Oral Health
4.
Musculoskelet Surg ; 101(1): 59-66, 2017 Apr.
Article in English | MEDLINE | ID: mdl-27757848

ABSTRACT

BACKGROUND: The purpose of this study was to compare the clinical and radiological outcomes of multiple small diameter drilling and core decompression with fibular strut grafting in the management of non-traumatic avascular necrosis (AVN) of the femoral head. MATERIALS AND METHODS: Outcomes of patients with AVN treated by multiple small diameter drilling (group 1) were compared retrospectively with patients treated by core decompression and fibular grafting (group 2). Harris hip score (HHS) was used to assess the clinical status pre- and postoperatively. Modified Ficat and Arlet classification was used to assess the radiological stage pre- and postoperatively. RESULTS: Forty-six patients (68 hips) were included in this study. Group 1 consisted of 33 hips, and group 2 consisted of 35 hips. In stages I and IIB, there was no statistically significant difference in the final HHS between the two groups. However, in stages IIA and III, hips in group 2 had a better final HHS (P < 0.05). In terms of radiographic progression, there was no statistical difference between hips in stages I, IIA and stage IIB. However, in stage III, hips belonging to group 2 had better results (P < 0.05). Kaplan-Meier survivorship analysis showed better outcome in group 2 in stage III (P < 0.05). CONCLUSIONS: Hips with AVN in the precollapse stage can be salvaged by core decompression with or without fibular grafting. Multiple small diameter drilling is relatively simple and carries less morbidity and hence preferred in stages I and II. However, in stage III disease, core decompression with fibular strut grafting gives better results.


Subject(s)
Decompression, Surgical/methods , Femur Head Necrosis/surgery , Fibula/transplantation , Adult , Disease Progression , Female , Femur Head Necrosis/diagnosis , Follow-Up Studies , Humans , Male , Middle Aged , Retrospective Studies , Treatment Outcome
6.
Clin Exp Hypertens ; 38(3): 268-77, 2016.
Article in English | MEDLINE | ID: mdl-27028574

ABSTRACT

Hypertension is a major public health problem in the developing as well as in developed countries due to its high prevalence and its association with coronary heart disease, renal disease, stroke, peripheral vascular disease, and related disorders. Essential hypertension (EH) is the most common diagnosis in this disease, suggesting that a monocausal etiology has not been identified. However, a number of risk factors associated with EH have also been identified such as age, sex, demographic, environmental, genetic, and vascular factors. Recent advances in molecular biological research had achieved clarifying the molecular basis of Mendelian hypertensive disorders. Molecular genetic studies have now identified mutations in several genes that cause Mendelian forms of hypertension in humans. However, none of the single genetic variants has emerged from linkage or association analyses as consistently related to the blood pressure level in every sample and in all populations. Besides, a number of polymorphisms in candidate genes have been associated with differences in blood pressure. The most prominent candidate has been the polymorphisms in the renin-angiotensin-aldosterone system. In total, EH is likely to be a polygenic disorder that results from inheritance of a number of susceptibility genes and involves multiple environmental determinants. These determinants complicate the study of blood pressure variations in the general population. The complex nature of the hypertension phenotype makes large-scale studies indispensable, when screening of familial and genetic factors was intended. In this review, recent genetic studies exploring the molecular basis of EH, including different molecular pathways, are highlighted.


Subject(s)
Hypertension , Renin-Angiotensin System/genetics , Adult , Essential Hypertension , Female , Genetic Association Studies , Genetic Linkage , Genetic Predisposition to Disease , Humans , Hypertension/epidemiology , Hypertension/genetics , Hypertension/physiopathology , Middle Aged , Phenotype , Polymorphism, Genetic , Risk Factors
7.
Spinal Cord ; 51(11): 815-8, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24042988

ABSTRACT

STUDY DESIGN: Prospective study. OBJECTIVES: In a prospective study, 45 consecutive cases of cervical spinal cord injury without radiographic evidence of trauma (SCIWORET) who were treated non-operatively were analyzed to correlate the magnetic resonance image findings with the initial neurological deficit and the extent of neurological recovery at 2 years. SETTING: University tertiary-care teaching hospital in South India. METHODS: The neurological status of patients who did not have any radiographic or computerized tomographic abnormality at the time of admission was assessed by ASIA Impairment Scale (AIS) modification of Frankel's grading. The spinal cord abnormality seen in the magnetic resonance imaging was noted. The neurological status at the end of 2 years was recorded. RESULTS: Twenty-seven of the 45 patients (60%) had cord oedema, 8 (17.77%) had cord contusion, 8 (17.77%) patients had a normal cord and 2 (4.44%) patients had cord swelling on the magnetic resonance image. Out of 27 patients who presented with cord oedema, 14 (31.11%) patients recovered from AIS D to AIS E and 6 (13.33%) patients did not recover and remained at AIS D. Seven (15.55%) patients who had a normal cord recovered completely to AIS E. Five (11.11%) patients who had contusion of the cord recovered up to AIS D. CONCLUSION: The initial neurological status correlates with magnetic resonance imaging findings. Subsequent neurological recovery is dependent on the type of cord damage and initial neurological status. The rate of recovery and the final motor outcome are inversely related to the length of cord involvement.


Subject(s)
Spinal Cord Injuries/surgery , Adolescent , Adult , Aged , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Prospective Studies , Radiography , Recovery of Function/physiology , Spinal Cord Injuries/diagnosis , Spinal Cord Injuries/diagnostic imaging , Treatment Outcome , Young Adult
8.
3 Biotech ; 3(6): 517-520, 2013 Dec.
Article in English | MEDLINE | ID: mdl-28324421

ABSTRACT

Breast cancer is the most common neoplasm affecting women in the western world with an average frequency of 1 in 11, developing the malignancy and it is second most common cancer in India. Variations in serum levels of biochemical parameters especially alkaline phosphatase (ALP) changes may be of great help in diagnosis of breast carcinoma. Serum ALP activity was assayed in 388 histopathologically proven breast cancer patients using spectrophotometric methods and monitored association with cancer stages. Breast cancer is a female-biased disease and our study was conducted in a group of female patients with mean age of 48.67 ± 8.32 years. A significant increase in levels of ALP (809.65 ± 145.97 IU/L) was observed in stage IV of the disease. The logistic regression study gave a significant result (P < 0.001) when we compared the group of ALP level (>500 IU/L) with metastatic presentation. The present study besides being cost effective suggested the usefulness of ALP in differentiating breast cancer stages and metastasis.

9.
J Nutr Health Aging ; 16(5): 437-41, 2012 May.
Article in English | MEDLINE | ID: mdl-22555786

ABSTRACT

OBJECTIVE: Poor dietary habits and nutritional intake are associated with a range of chronic diseases. Oral health may be directly associated with general health status, as well as related to diet. The aims are to assess dietary, self-reported oral health and socio-demographic predictors of general health status among older adults. DESIGN: Cross-sectional mailed survey. PARTICIPANTS: A random sample of adults in Adelaide, South Australia aged 60-71 years in 2008. MEASUREMENTS: Health status was measured using the EuroQol (EQ-5D). Compliance with dietary guidelines was measured using a 16-item index of grocery purchasing. Oral health was measured by self-reported number of teeth, oro-facial pain and sore gums. Socio-demographics included age, sex, birth place and subjective social status. RESULTS: Responses were collected from n=444 persons (response rate = 68.8%). The average EQ-5D score was 0.80 (se=0.01). Unadjusted analyses showed (p<0.05) EQ-5D scores were lower in the bottom tertile of compliance with dietary guidelines, for those reporting oro-facial pain, sore gums and fewer teeth, and for the lower social status group. Multivariate analyses showed (p<0.05) lower compliance with dietary guidelines was associated with poorer general health (beta=-0.10), as was oro-facial pain (beta=-0.11), sore gums (beta=-0.17), and lower social status (beta=-0.28). CONCLUSIONS: Socio-economic status, oral symptoms and compliance with dietary guidelines were associated with general health status.


Subject(s)
Diet , Energy Intake , Feeding Behavior , Health Status , Oral Health , Periodontal Diseases/complications , Social Class , Aged , Cross-Sectional Studies , Facial Pain/complications , Female , Gingiva , Guidelines as Topic , Humans , Male , Middle Aged , Multivariate Analysis , Patient Compliance , Self Report , South Australia , Tooth , Tooth Loss/complications
10.
ACS Appl Mater Interfaces ; 3(8): 2973-8, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21790138

ABSTRACT

Charge injection and transport in bottom-contact regioregular-poly(3-hexylthiophene) (rr-P3HT) based field-effect transistors (FETs), wherein the Au source and drain contacts are modified by self-assembled monolayers (SAMs), is reported at different channel length scales. Ultraviolet photoelectron spectroscopy is used to measure the change in metal work function upon treatment with four SAMs consisting of thiol-adsorbates of different chemical composition. Treatment of FETs with electron-poor (electron-rich) SAMs resulted in an increase (decrease) in contact metal work function because of the electron-withdrawing (-donating) tendency of the polar molecules. The change in metal work function affects charge injection and is reflected in the form of the modulation of the contact resistance, R(C). For example, R(C) decreased to 0.18 MΩ in the case of the (electron-poor) 3,5-bis-trifluoromethylbenzenethiol treated contacts from the value of 0.61 MΩ measured in the case of clean Au-contacts, whereas it increased to 0.97 MΩ in the case of the (electron-rich) 3-thiomethylthiophene treated contacts. Field-effect mobility values are observed to be affected in short-channel devices (<20 µm) but not in long-channel devices. This channel-length-dependent behavior of mobility is attributed to grain-boundary limited charge transport at longer channel lengths in these devices.


Subject(s)
Thiophenes/chemistry , Transistors, Electronic , Electrons , Gold/chemistry
11.
Aust Dent J ; 55(2): 143-9, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20604755

ABSTRACT

BACKGROUND: The aim of this study was to examine consumption of fruit and vegetables in relation to tooth loss and income. METHODS: Data were collected in 2004-06, using a three-stage, stratified clustered sample, involving a computer-assisted telephone interview (CATI), oral examination and mailed questionnaire followed by a food frequency questionnaire. RESULTS: A total of 14 123 adults responded to the CATI (49% response) of whom 5505 (44% of those interviewed) agreed to undergo an oral epidemiological examination. In the nutrition sub-study, a total of n = 1218 persons were approached in New South Wales and Queensland, with n = 1129 responding (92.7% response rate). Among respondents aged 55 years or more 34.5% had <21 teeth. Adjusting for income the prevalence of infrequent consumption ('never or less than once a month') was associated with [PR = prevalence ratio (95% CI)] fewer teeth for the fruits, 'peach, nectarine, plum, apricot' PR = 1.91 (1.12, 3.25) and 'grapes or berries' PR = 1.69 (1.03, 2.76), and for the vegetables 'stir-fried or mixed' PR = 2.34 (1.14, 4.78), 'sweetcorn' PR = 1.45 (1.001, 2.10), 'mushrooms' PR = 1.62 (1.05, 2.50), 'lettuce' PR = 3.99 (1.31, 12.17) and 'soy beans' PR = 1.11 (1.01, 1.21). CONCLUSIONS: An inadequate dentition was associated with lower consumption of a range of fruits and vegetables indicating that dentition-related impairment of chewing ability could have adverse consequences on nutritional intake among Australian adults.


Subject(s)
Feeding Behavior , Fruit , Social Class , Tooth Loss/epidemiology , Vegetables , Agaricales , Australia/epidemiology , Brassica , Female , Humans , Income , Lactuca , Male , Middle Aged , New South Wales/epidemiology , Prunus , Queensland/epidemiology , Solanaceae , Solanum tuberosum , Glycine max , Tooth Loss/classification , Vitis , Zea mays
12.
Caries Res ; 41(1): 34-42, 2007.
Article in English | MEDLINE | ID: mdl-17167257

ABSTRACT

Pre-eruptive fluoride exposure has been shown to be important for caries prevention. This paper aimed to determine the relative effects of water fluoride exposure during crown completion (CC) and maturation on caries experience in first permanent molars. Parental questionnaires covering residential history were linked to oral examinations of 19,885 6- to 15-year-old Australian children conducted in 1992 by the School Dental Services of South Australia and Queensland. The percentage of lifetime exposed to optimally fluoridated water at CC, maturation (MAT) and post-eruption (POST) was calculated. Combined exposure variables describing different levels of CC, maturation and post-eruption were created using a threshold exposure of 50%. Compared to the reference of CC <50%/MAT <50%/POST <50%, the categories CC > or =50%/MAT <50%/POST > or =50% [rate ratio (RR) 0.52], CC > or =50%/MAT > or =50%/POST <50% (RR 0.61) and CC > or =50%/MAT > or =50%/POST > or =50% (RR 0.67) had the strongest caries-preventive effect, followed by CC > or =50%/MAT <50%/POST <50% (RR = 0.79) and CC <50%/MAT > or =50%/POST > or =50% (RR = 0.81) in negative binomial regression models (p < 0.05). The categories CC <50%/MAT > or =50%/POST <50% (RR = 0.85) and CC <50%/MAT <50%/POST > or =50% (RR = 0.84) had weaker, non-significant caries-preventive effects. In conclusion a high exposure at CC was important for caries prevention irrespective of the effect of exposure at maturation and post-eruption. The strongest caries-preventive effect was produced by a high exposure at CC supplemented by a high exposure at maturation and/or post-eruption, but the latter two phases could not produce a significant caries-preventive effect on their own. Since most of the caries occurred on pit and fissure surfaces, the findings relate to this class of lesion.


Subject(s)
Cariostatic Agents/therapeutic use , Dental Caries/drug therapy , Fluorides/therapeutic use , Tooth Crown/drug effects , Tooth Eruption , Adolescent , Age Factors , Child , Dental Caries/epidemiology , Dental Caries/prevention & control , Epidemiologic Methods , Female , Fluoridation , Humans , Male , Molar/drug effects , Time Factors , Tooth Crown/growth & development , Toothbrushing
13.
Int J Oral Maxillofac Surg ; 33(7): 700-8, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15337185

ABSTRACT

This study was set-up to describe main areas of service by patient and visit characteristics and compare trends in services between 1990 and 2000. All registered oral and maxillofacial surgeons in Australia were surveyed in 1990 and 2000 using mailed self-complete questionnaires. Service provision data were collected from a one-week log. Data were available from 79 surgeons from 1990 (response = 73.8%) and 116 surgeons from 2000 (response = 65.1%). Service distributions were dominated by dentoalveolar surgery in 1990 (66.6%) and 2000 (63.5%). Multivariate analysis showed: patient age, location of visit (office/theatre/inpatient facility) and referral source (general/specialist and dental/medical) were associated with all five main areas of service; type of visit (consult/operation/review) was associated with four main areas; patient sex and place of visit (private/public) was associated with three main areas; the only significant change over time was an increased percentage of orthognathic surgery, odds ratio = 1.4 (95% CI: 1.1-1.7) times higher in 2000 compared to 1990. Main areas of service were associated with a range of explanatory variables such as age and sex of patients, and place, location and type of visit, and referral source. However, the distribution of services remained relatively stable over time.


Subject(s)
Practice Patterns, Dentists'/statistics & numerical data , Surgery, Oral/statistics & numerical data , Adolescent , Adult , Aged , Australia , Child , Child, Preschool , Female , Health Facilities/statistics & numerical data , Humans , Logistic Models , Male , Middle Aged , Private Practice/statistics & numerical data , Public Health Dentistry/statistics & numerical data , Surveys and Questionnaires
14.
Int J Oral Maxillofac Surg ; 33(6): 598-605, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15308261

ABSTRACT

This study was undertaken to describe practice patterns of oral and maxillofacial surgeons in Australia and compare trends over time. All registered oral and maxillofacial surgeons in Australia were surveyed in 1990 and 2000 using mailed self-complete questionnaires. Data were available from 79 surgeons from 1990 (response rate = 73.8%) and 116 surgeons from 2000 (response rate = 65.1%). In both 1990 and 2000 the majority of surgeons worked 80+% of the time in the private sector (64.1 and 71.4%), had 80+% referrals from dental versus medical sources (74.0 and 74.7%), and had 80+% of patients from dentoalveolar rather than major maxillofacial surgery (70.7 and 69.7%). The percentage of dual qualified (dental plus medical degree) surgeons increased from 2.5% in 1990 to 17.1% in 2000 (P < 0.05; chi2). In 2000, surgeons who worked less than 80% in the private sector were more likely to report being overworked (57.9%) and that more surgeons were required in the public sector (65.0%) than those who worked 80% or more private (17.0 and 24.0%, respectively). Multivariate linear regressions of annual non-dentoalveolar surgical procedures per surgeon showed (P < 0.05) higher provision of implant (beta = 0.362), TMJ (beta = 0.267) and bone graft surgery (beta = 0.208) in 2000 compared to 1990, and higher provision of orthognathic (beta = 0.199), implant (beta = 0.194) and bone graft surgery (beta = 0.289) by dual qualified surgeons compared to those with only dental qualifications. Despite the mix of cases remaining predominantly dentoalveolar there was some change over time for selected non-dentoalveolar surgical procedures, with growth in the percentage of medically qualified surgeons and differences in surgery rates by qualification.


Subject(s)
Practice Patterns, Dentists'/statistics & numerical data , Surgery, Oral/statistics & numerical data , Adult , Australia , Female , Humans , Licensure, Dental/statistics & numerical data , Licensure, Medical/statistics & numerical data , Linear Models , Male , Middle Aged , Multivariate Analysis , Practice Patterns, Dentists'/trends , Private Practice/statistics & numerical data , Public Health Dentistry/statistics & numerical data , Referral and Consultation/statistics & numerical data , Surgery, Oral/trends , Surveys and Questionnaires , Workload/statistics & numerical data
15.
J Public Health Dent ; 63(1): 11-9, 2003.
Article in English | MEDLINE | ID: mdl-12597581

ABSTRACT

OBJECTIVES: Previous studies have attributed the caries-preventive effects of preeruption (PRE) and posteruption (POST) exposure to fluoridated water based on data collected before and after the commencement or discontinuation of water fluoridation. This study aims to determine the relative pre- and posteruption exposure effects of fluoridated water on caries experience of 6-15-year-old Australian children based on individual residential histories. METHODS: Parental questionnaires covering residential history of participants were linked to their oral examinations conducted between June 1991 and May 1992 by the School Dental Services of South Australia and Queensland. Percentage of lifetime exposed to optimally fluoridated water PRE and POST was calculated with respect to the eruption age for first permanent molars. Combined pre- and posteruption categories were created to test PRE against POST exposure: PRE & POST = 0, PRE < POST, PRE = POST in the range 0-90 percent of lifetime exposure, PRE > POST, and PRE & POST > or = 90 percent lifetime exposure. These categories were used as indicator variables with PRE and POST = 0 as reference in an analysis of first permanent molar DMFS scores. The linear regression model controlled for important potential confounders. RESULTS: Participation rates were 69.7 percent in South Australia and 55.6 percent in Queensland with 9,690 and 10,195 participants, respectively. Pre- and posteruption exposures were strongly correlated (r =. 74; P < .01). Compared to the reference, the categories PRE > POST, PRE = POSTin the range 0-90 percent, and PRE and POST > or = 90 percent showed significantly lower caries levels. CONCLUSIONS: The findings indicated that preeruption exposure was required for a caries-preventive effect and that exposure after eruption alone did not lower caries levels significantly. However, the maximum caries-preventive effects of fluoridated water were achieved by high pre- and posteruption exposure.


Subject(s)
Dental Caries/prevention & control , Fluoridation , Adolescent , Age Factors , Child , DMF Index , Dental Caries/epidemiology , Female , Humans , Linear Models , Male , Queensland/epidemiology , Residence Characteristics , South Australia/epidemiology , Surveys and Questionnaires , Tooth Eruption
16.
Tree Physiol ; 15(3): 197-202, 1995 Mar.
Article in English | MEDLINE | ID: mdl-14965976

ABSTRACT

The effects of light, moderate and heavy branch pruning or lopping treatments (resulting in removal of 28-31, 56-60 and 80-82% of the foliage, respectively, unlopped control = 0%) were studied in 3-year-old black alder (Alnus glutinosa L. Gaertn.) plants. Within 24 h of lopping, transpiration rates decreased and water potentials increased. The effects of lopping continued for 48 days. The improved water status of the lopped plants enhanced water-use efficiency during the first 30 days. Regrowth was related to a combination of enhanced net assimilation rates during the first 30 days after lopping, use of current photoassimilates and stored carbohydrates in the roots (particularly in medium and heavily lopped plants) for the production of new leaf area, and delayed leaf senescence. The lightly and moderately lopped plants developed 62 and 57% more leaf area, respectively, than the unlopped plants, but total leaf area development was slower in the heavily lopped plants. Lightly lopped plants produced total biomass equivalent to that of unlopped plants, but the moderately and heavily lopped plants produced less biomass than the unlopped plants. During the first 30 days after lopping, there was a net loss of nodule dry matter and recovery to control values did not occur during the period of study. Immediately (24 h) after lopping, more (14)C-photosynthate was translocated to the roots of lopped plants than to the roots of unlopped plants. When a branch near the base of the main stem was fed (14)CO(2), (14)C-photosynthate translocation to the shoot increased with increasing intensity of lopping, at 50 days after lopping.

17.
Talanta ; 39(8): 971-5, 1992 Aug.
Article in English | MEDLINE | ID: mdl-18965480

ABSTRACT

A very simple, highly-sensitive and selective quenchofluorimetric method for the rapid determination of molybdenum(VI) in aqueous media is described. The method is based on the instantaneous quenching action by the metal-ion upon the native fluorescence of bathophenanthrolinedisulphonate (4,7-diphenyl-1,10-phenanthrolinedisulphonate) solution [lambda(ex) (max) 288 nm; lambda(em) (max) 444.8 nm] in the optimum pH-range of 3.0-3.7 at room temperature (25 +/- 5 degrees ). The fluorescence quenching is co-linear in the range of 0.01-1.0 ppm molybdenum. Large excesses of over 50 cations, anions and some common complexing agents were found to have no interference. Cu, Ni, Co, Fe and V can be tolerated only up to the corresponding amount of molybdenum. Interference from greater amounts can however be removed by a one-step ion-exchange separation process. The developed method was successfully tested over several standard alloys, synthetic mixtures of various compositions, factory effluents and in spiked environmental waters.

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