Use Of ND Research Articles

Simplified method for determining dose to a non-water phantom through the use of ND,w and IAEA TRS 483 for the GammaPod.

GammaPod, a breast stereotactic radiosurgery device, utilizes 25 rotating Co-60 sources to deliver highly conformal dose distributions. The GammaPod system requires that reference dosimetry be performed in a specific vendor-supplied poly-methylmethacrylate (PMMA) phantom. The nonstandard nature of GammaPod dosimetry, in both the phantom material and machine-specific reference (msr), prohibits use of the American Association of Physicists in Medicine Task Group 51 (TG-51) protocol. This study proposes a practical method using TRS 483 to make the reference dosimetry procedure simpler and to reduce overall uncertainties. The dose to PMMA (DPMMA) is determined under msr conditions using TRS 483 with an Exradin A1SL chamber placed in a PMMA phantom. The conversion factor, which converts from the dose-to-water (Dw) in broad-beam Co-60 reference geometry to DPMMA in the msr small field Co-60 (Qmsr) geometry, is derived using the Monte Carlo simulations and procedure described in TRS 483. The new conversion factor value for an Exradin A1SL chamber is 0.974. When combined with ND,w, DPMMA differs by 0.5% from the TG-21/Nx method and 0.2% from the IROC values. Uncertainty decreased from 2.2% to 1.6%. We successfully implemented TRS 483 reference dosimetry protocols utilizing ND,w for the GammaPod in the PMMA phantom. These results show not only agreement between measurements performed with the previously published method and independent thermoluminescent dosimetry measurements but also reductions in uncertainty. This also provides readers with a pathway to develop their own IAEA TRS 483 factor for any new small field machine that may be developed.

Under What Conditions Can We Trust Retrieved Cloud Drop Concentrations in Broken Marine Stratocumulus?

AbstractIn this study, we show how to obtain more reliable satellite‐retrieved cloud drop number concentrations (Nd) from Moderate Resolution Imaging Spectroradiometer (MODIS) standard cloud products. Nd is important as a fundamental cloud property that determines cloud albedo, precipitation‐forming processes, cloud longevity, and fractional cover, all of which determine cloud radiative effects. Nd is determined by cloud base aerosols and updrafts. Satellite retrievals of Nd for marine stratocumulus clouds are performed based on the assumption of a nearly adiabatic cloud column. The retrievals, however, are fraught with problems that cause large biases (e.g., the retrieved Nd for partially filled cloudy pixels are less than one third of the retrieved Nd for the convective cores) and limit the usefulness of Nd, especially in broken cloud fields. The Nd of the brightest 10% of cloudy pixels are selected because the brightest clouds are the convective cores that most closely follow adiabatic parcels, a key assumption of our retrieval. It is shown that this criterion is representative of pixels that are also fully surrounded by cloudy pixels (Nd agreement within 5%).

Clinical comparison of patients with refractory angina with and without the nursing diagnosis of activity intolerance

Refractory angina is resistant to all of the conventional treatments available for coronary artery disease, including medication, percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) (Mannheimer et al. 2002). Patients with refractory angina generally have limited functional capacity and restricted activities (Sevinc & Akyol 2010), which can be evaluated through stress tests and indicated by determining angina [Canadian Cardiology Society (CCS)] and heart failure (New York Heart Association [NYHA]) classes. The ND of activity intolerance, defined as insufficient physiological or psychological energy to endure or complete ten required or desired daily activities, might be appropriate for these patients (NANDA-I 2008). The defining characteristics of the ND of activity intolerance are electrocardiographic changes reflecting ischemia, electrocardiographic changes reflecting arrhythmia, exertion discomfort and/or dyspnea, verbal reports of fatigue and/or weakness, abnormal heart rate and/or blood pressure response to activity (NANDA-I 2008), which indicate the potential suitability of this particular ND for patients with refractory. It is noteworthy that identification the ND is important because nurses prescribe nursing interventions based on this and consequently better care priorities are established (Muller-Staub et al. 2009). Systematised care using the nursing process, which includes the identification of ND, was studied (Muller-Staub et al. 2009, Martins et al. 2010) and the findings confirmed that the appropriate use of ND contributes to the scientific foundation for its use.

Early Surgical Laser-Assisted Management of Bisphosphonate-Related Osteonecrosis of the Jaws (BRONJ): A Retrospective Analysis of 101 Treated Sites with Long-Term Follow-Up

The management of bisphosphonate-related osteonecrosis of the jaws (BRONJ) is still controversial. The purpose of this study was to compare surgical and nonsurgical approaches to the treatment of BRONJ and the possible usefulness of Nd:YAG and Er:YAG lasers. One hundred and twenty-eight patients (33 males, 95 females; 52 with diagnosis of multiple myeloma, 53 with diagnosis of bone metastasis, and 23 with diagnosis of osteoporosis) affected by BRONJ were evaluated at the Unit of Oral Pathology and Medicine and Laser-Assisted Surgery of the University of Parma, Italy, between January 2004 and July 2009. Overall number of BRONJ sites was 151, and number of treated sites was 101. In order to assess the efficacy of different treatments, sites were subclassified as follows: Group 1 (G1): 12 sites treated with medical therapy; Group 2 (G2): 27 sites treated with medical therapy associated with low level laser therapy (LLLT); Group 3 (G3): 17 sites treated with a combination of medical and surgical therapy; Group 4 (G4): 45 sites treated with a combination of medical therapy, surgical (including laser-assisted) therapy, and LLLT. Outcome of treatment was assessed using the staging system proposed by Ruggiero et al. Transition from a higher stage to a lower one for at least 6 months was considered as clinical improvement and suggestive of a successful treatment. Clinical improvement was achieved in 3 out of 12 (25%) BRONJ sites in G1. Sites if G2 with an improvement were 18 out of 27 (66%). Nine out 17 BRONJ sites (53%) in G3 had a transition to a lower stage after treatment. For sites in G4, a clinical improvement was recorded in 40 out of 45 cases (89%). In our experience, the percentage of success obtained with a combined approach based on medical therapy, surgical (including laser-assisted) therapy, and LLLT (G4) is significantly higher than the percentage of improvement obtained in G1, G2, and G3.

Nd:Yag laser em catarata infantil

To describe and to evaluate the usefulness of Nd: Yag laser in pseudophakic children. Twenty-four eyes of 22 pseudophakic patients with posterior capsule opacification, that had been submitted to posterior capsulotomy with Nd:Yag-laser were prospectively analyzed at the Infantile Cataract Section of the Federal University of São Paulo/Paulista School of Medicine, from June 2001 to March 2003. Age at surgery, IOL type, IOL placement, time interval between surgery and posterior capsule opacification, energy needed (mJ), laterality, initial and final visual acuity were analyzed. Capsulotomy was performed in all pseudophakic eyes. Four (16.6%) eyes received polyacrylic implants and 18 (75%) PMMA lenses. Twelve IOL were in the capsular bag and nine in the ciliary sulcus. The laser energy level required was 0,8 mJ to 2 mJ per spot, total amount was 100 mJ. Nd:Yag laser was feasible in 22 (91.6%) eyes. Only two (8.3%) eyes required capsulotomy surgery. The obtained results suggest that Nd:Yag laser capsulotomy may be a good option to improve visual acuity in pseudophakic children.

Removal of Two Types of Root Canal Filling Material Using Pulsed Nd:YAG Laser Irradiation

The aim of this study was to examine the usefulness of a pulsed Nd:YAG laser in removing two types of endodontic obturation material from the root canal in vitro. Recently, a fine flexible glass fiber made of quartz has been developed to transmit the laser beam more effectively and permit its concentration in a specific area. This has increased the potential usefulness of the Nd:YAG laser in root canal treatment. The time required for removing the root canal obturation material (Gutta-percha cones and, Sealapex or AH26) by means of either Nd:YAG laser irradiation or a conventional method (Gates Glidden drills and K files) was measured. Contact microradiography was used to assess the radiopacity of the root canals before and after the removal of obturation material. The surfaces of the root canal after removal of the obturation materials were also observed by scanning electron microscopy. Although none of the methods used in this study resulted in complete removal of debris from the root canal wall, the time required for the removal of any of the root canal obturation materials using laser ablation was significantly shorter than that required using the conventional method (p < 0.05). It appeared that some orifices of the dentinal tubules were blocked with melted dentin following laser irradiation. Nd:YAG laser irradiation is an effective tool for the removal of root canal obturation materials, and may offer advantages over the conventional method.

Interaction between Nitrogen Deficit of a Plant and Nitrogen Content in the Old Leaves

We examined changes in nitrogen content of the first leaves in relation to growth and nitrogen status of sunflower (Helianthus annuus L.) plants that were raised hydroponically at two irradiance levels (high and low light, HL and LL) and at two nitrogen concentrations (high and low nitrogen, HN and LN). Initial increases in total dry mass and total nitrogen of the whole plant were faster in HL-plants than in LL-plants irrespective of nitrogen supply, but in LN-plants the increase in total nitrogen was soon blunted. When plants grown under the same irradiance were compared, nitrogen content of the first leaves (leaf N) decreased faster in LN-plants than in HN-plants, while for the plants grown at the same nitrogen concentrations, it decreased faster in HL-plants than in LL-plants. Since these changes in leaf N were not explained solely by the changes in plant dry mass or plant nitrogen, we introduced an index, ‘nitrogen deficit (ND*)’, to quantify nitrogen deficit of the whole plant. ND* was expressed as ND*(t)=[Nmax–N(t)]×DM(t), where Nmax and N(t) were nitrogen contents in the young, expanding leaves that had just unfolded to expand, at the initial stage with sufficient nitrogen and at time t, respectively, and DM(t), plant dry mass at t. The decrease in leaf N was expressed as a liner function of ND* irrespective of the growth conditions, which indicates validity of this index. Limitation of the use of ND*, and mechanisms by which leaves sense nitrogen demand are also discussed.

Making use of ND — YAG laser SHARPLAN 2100 when treating the pneumooncologically ill — A year's experience and results

Making use of ND — YAG laser SHARPLAN 2100 when treating the pneumooncologically ill — A year's experience and results

Use of ND:YAG laser in treatment of bladder cancer

A total of 53 patients were treated with neodymium:yttrium-aluminum garnet (Nd: YAG) laser and followed up for two years. Three patients had carcinoma in situ (CIS); 4 had Ta lesions; and 28 had TINξMo, 8 had T2NξMo, and 10 had T3NξMo lesions. The patients with CIS received a combination of Nd:YAG laser and intravesical bacillus Calmette Guérin (BCG) instillation. The remainder of the patients received no supplementary chemotherapy. No tumor recurrence was noted in those with Ta lesions. Tumor recurred in 18 per cent of patients with TI lesions, and 33 per cent of those with T2 lesions; 80 per cent of patients with T3 lesions had resistant or residual tumors. In patients with CIS, there was no tumor recurrence. Nd:YAG laser is effective in Ta, Tl, and T2 bladder cancers, with low recurrence rate and minimal complications. In very select, high-risk patients with small lesions, and in those who refuse cystectomy, there may be a place for laser therapy for either palliation or definitive treatment of T3 invasive tumors of the bladder.

Elucidation de structure et comportement de produits naturels sous ionisation chimique—II: Aminolyse et substitution nucleophile produites—en phase gazeuse avec l'ammoniac—sur la cinerubine a

The structure of cinerubine A has been studied by chemical ionisation mass spectrometry. In the NH 3/Cl mode, this type of compound with polyfunctional sites undergoes as aminolysis reaction, i.e. hydroxyl and carbonyl groups are substituted by NH 3. The protonated molecular ions formed in the ion source fragment to give intense ions which provide useful structural information. Unimolecular fragmentations in the first field-free region permit determination of the reactive sites. Use of ND 3 as reagent gas provides information on the number of mobile H atoms and permits the assignment of structure for these ionic species.