Nuclear Charge Radii of the Nickel Isotopes

Collinear laser spectroscopy is performed on the nickel isotopes ^{58-68,70}Ni, using a time-resolved photon counting system. From the measured isotope shifts, nuclear charge radii R_{c} are extracted and compared to theoretical results. Three ab initio approaches all employ, among others, the chiral interaction NNLO_{sat}, which allows an assessment of their accuracy. We find agreement with experiment in differential radii δ⟨r_{c}^{2}⟩ for all employed ab initio methods and interactions, while the absolute radii are consistent with data only for NNLO_{sat}. Within nuclear density functional theory, the Skyrme functional SV-min matches experiment more closely than the Fayans functional Fy(Δr,HFB).

Pulse to pulse control for highly precise and efficient micromachining with femtosecond lasers.

Micromachining with high repetition rate femtosecond lasers and galvo scanners shows some limitations in the pulses positioning accuracy due to the galvo mirrors acceleration. This is particularly evident during scan speed or direction changes, resulting in a poor quality and overtreatment e.g. in corners. Several scanning approaches have been proposed to tackle these issues like the so-called skywriting (SW) and the pulse-on-demand (POD) being the last limited to ns lasers, moderate pulse repetition rates and scan speeds. Recently, POD approach has been extended to femtosecond laser sources with high power and high repetition rate. Here, for the first time, we explored the huge potential in laser micromachining of femtosecond POD technology associated to a fast galvo scanner. We tested an innovative set-up allowing for precise laser triggering at the requested time and position for MHz repetition rate and scan speed as high as 20 m/s. The pulse position accuracy of the system has been estimated to be ≤ 1µm whilst performances have been evaluated in comparison to conventional scanning and SW. Finally, we report the results of an engraving test on stainless steel. The advantages of the approach we propose are clearly shown in terms of machining quality and precision with respect to conventional scanning and reduction of the processing time by ≈ 40% with respect to SW.

Charge Radius of the Short-Lived

We present the first laser spectroscopic measurement of the neutron-rich nucleus ^{68}Ni at the N=40 subshell closure and extract its nuclear charge radius. Since this is the only short-lived isotope for which the dipole polarizability α_{D} has been measured, the combination of these observables provides a benchmark for nuclear structure theory. We compare them to novel coupled-cluster calculations based on different chiral two- and three-nucleon interactions, for which a strong correlation between the charge radius and dipole polarizability is observed, similar to the stable nucleus ^{48}Ca. Three-particle-three-hole correlations in coupled-cluster theory substantially improve the description of the experimental data, which allows to constrain the neutron radius and neutron skin of ^{68}Ni.

Laser Spectroscopy of Neutron-Rich Tin Isotopes: A Discontinuity in Charge Radii across the N=82 Shell Closure.

The change in mean-square nuclear charge radii δ⟨r^{2}⟩ along the even-A tin isotopic chain ^{108-134}Sn has been investigated by means of collinear laser spectroscopy at ISOLDE/CERN using the atomic transitions 5p^{2} ^{1}S_{0}→5p6 s^{1}P_{1} and 5p^{2} ^{3}P_{0}→5p6s ^{3}P_{1}. With the determination of the charge radius of ^{134}Sn and corrected values for some of the neutron-rich isotopes, the evolution of the charge radii across the N=82 shell closure is established. A clear kink at the doubly magic ^{132}Sn is revealed, similar to what has been observed at N=82 in other isotopic chains with larger proton numbers, and at the N=126 shell closure in doubly magic ^{208}Pb. While most standard nuclear density functional calculations struggle with a consistent explanation of these discontinuities, we demonstrate that a recently developed Fayans energy density functional provides a coherent description of the kinks at both doubly magic nuclei, ^{132}Sn and ^{208}Pb, without sacrificing the overall performance. A multiple correlation analysis leads to the conclusion that both kinks are related to pairing and surface effects.

Coincidence of Tracheobronchomegaly (Mounier-Kuhn Syndrome) and Juvenile Idiopathic Arthritis.

Mounier-Kuhn syndrome (MKS) or tracheobronchomegaly includes clinical and radiographic findings of tracheobronchial dilatation and recurrent respiratory infections. MKS is a very rare pathology, especially in the paediatric age group which makes it a diagnostic challenge. A 4-year-old girl suffered from dyspnea, recurrent respiratory infections and joint pain. Chest radiography detected peribronchial reinforcement and CT-scan revealed extended tracheal dilatation and bronchiectasis. In addition to MKS our patient was diagnosed with juvenile idiopathic arthritis (JIA) and scleroderma. MKS can be caused by congenital disorder or acquired aetiology. Several connective tissue diseases have been associated with MKS but no cases of JIA or scleroderma are described previously. Our case illustrates that patients who suffer from recurrent respiratory infections with unsatisfactory evolution and unspecific chest X-ray alteration, MKS always has to be considered in the differential diagnosis particularly in patients who suffer from connective tissue diseases.

Novel organically linked ZnII hydrogenselenite coordination polymers: synthesis, characterization, and efficient TiO2 photosensitization for enhanced photocatalytic hydrogen production.

This study focused on the solvothermal synthesis, characterization, and photocatalytic activities of two novel coordination polymers, namely [Zn(µ-HSeO3)2(bipy)]n (1) and [Zn(µ-HSeO3)2(phen)]n (2). These compounds represent the first organically linked ZnII hydrogenselenite coordination polymers. The synthesis of compounds 1 and 2 involved the addition of 2,2'-bipyridine and 1,10-phenanthroline, respectively, to SeO2 and ZnO in methanol as the solvent. The novel hydrogenselenite compounds were thoroughly characterized using spectroscopic and crystallographic methods. The photocatalytic solids (TiO2-1A and TiO2-2A) were prepared by immobilizing compounds 1-2 onto TiO2 through the sol-gel approach. These photocatalysts were then evaluated for hydrogen evolution via water splitting using a 300 W Hg/Xe lamp as the irradiation source. Among the newly synthesized photocatalytic materials, TiO2-1A demonstrated auspicious photocatalytic performance for hydrogen gas production. Its catalytic activity overcame the observed for the pure solid support TiO2 and Degussa P25 (commercial titania), making compound 1 a particularly attractive TiO2 photosensitizer. Additionally, TiO2-1A exhibited superior photocatalytic activity compared to TiO2-2A. The latter performed better than freshly prepared TiO2, approaching that of Degussa P25. These findings highlight the potential of compound 1 as an effective photosensitizer for TiO2-based photocatalysis, making it a promising candidate for applications in clean energy generation, specifically in hydrogen production by water splitting.

rac-2-[(2-Chloro-phen-yl)(4-chloro-phen-yl)meth-yl]-1,3-dioxolane.

The title compound, C(16)H(14)Cl(2)O(2), is a chiral mitotane derivative that contains a dioxolane ring and crystallizes from methanol as a racemic mixture. It was obtained in high yield from mitotane and ethyl-eneglycol in alkaline medium, followed by neutralization with sulfuric acid and extraction with ethyl acetate. The mol-ecular structure is stabilized by an intra-molecular C- H⋯ O hydrogen bond. The dihedral angle between the aromatic rings is 80.1 (2)°. The dioxolane ring adopts a puckered envelope conformation with an O atom as the flap.

Cultural and technology elucidation of the Tupi-Guarani tradition through analysis of potsherds from Travessão do Rio Vermelho site (Santa Catarina - Brazil) by spectroscopy, SEM-EDS and chemometrics.

Ceramic fragments can provide an insight into the ancient culture and practices of groups of humans and their way of life (technology, cultural identity, social organization, habitation and economy). Scientific analysis can be used to obtain information on the ceramic production process, as well as the specificities of the material employed. In this research, all samples of archaeological potsherd from the Tupi-Guarani tradition were analyzed in order to identify and to characterize the structures, morphologies and the elemental composition by using by scanning electron microscopy (SEM-EDS) and multivariate statistical methods (PCA and HCA). FTIR spectroscopy revealed the presence of an organic residue in three samples along with carbonates, clay minerals, quartz and hematite. In addition, the presence of the stretching attributed to water molecules in crystalline systems was observed. Also, the presence of TiO2 in the anatase polymorphic form was detected using µ-Raman spectroscopy. These results indicate a firing temperature of between 800 and 1000 °C. In relation to the morphology, all samples revealed amorphous structures presenting isolated and heterogenic particles of different forms and sizes, and the EDS spectrum confirmed the elements present in the molecular structures elucidated by vibrational spectroscopy. The multivariate analysis has confirmed the correlation between the elemental compositions of ceramics collected from two different sites: a mountain region and a coastal area in Santa Catarina State, Brazil.

Isolation and partial characterization of two abnormal human plasma lipoproteins: LP-X1 and LP-X2.

Two abnormal lipoproteins (LP-X1 and LP-X2) rich in free cholesterol and phospholipid have been isolated from the plasma of nine different patients with obstructive jaundice. As isolated, both lipoproteins were devoid of low density lipoproteins as judged by agar electrophoresis. In addition, they were free of apoB as judged by double immunodiffusion. However, LP-X1 exhibited a higher phospholipid to protein ratio and a lower hydrated density than LP-X2. The levels of LP-X1 and LP-X2 in plasma were measured in three patients studied for 14 days after corrective surgery for obstructive liver disease. The level of both these abnormal lipoproteins decreased after surgery until the twelfth day when they were completely absent from the plasma of these patients. The rates of this decrease for the two particles are significantly different. These differences in metabolic, chemical, and physical properties of LP-X1 and LP-X2, establish their identity as two distinct and unique lipoprotein particles.

Acid cholesterol ester and glycerol ester hydrolase activities. Evidence for the individuality of these enzymes in human mononuclear leucocytes.

Hydrolysis of cholesterol oleate and glycerol trioleate was measured in homogenates of human leucocytes at optimum pH of 4.0 and 5.25, respectively. Both enzyme activities appeared to reside in the 15,000 x g, 20-min fraction of mononuclear leucocytes. Solubilization of cholesterol ester hydrolase activity was strongly dependent on the detergent to protein ratio, showing optimal solubilization at weight ratios of 1.0 in cell homogenates and of 3.0 in the 15,000 x g, 20-min fraction, whereas solubilization of glycerol ester hydrolase was independent to protein ratio over the tested range of 0.3 to 5.8. Using a sequential solubilization procedure, about 60% of the granule proteins as well as 88% of glycerol ester hydrolase activity were solubilized at a detergent to protein ratio of 0.3, whereas cholesterol ester hydrolase activity was solubilized from the remaining membranes at a ratio of about 3.0. Thus, the acid glycerol ester hydrolase and acid cholesterol ester hydrolase were related to different proteins. Since solubilization of cholesterol ester hydrolase required drastic treatment, it is suggested that this enzyme is related to a protein within the lysosomal membrane.

Characterization and partial purification of acid lipase from human leucocytes.

Hydrolysis of glycerol trioleate by human leucocytes was characterized and the enzymes responsible for this activity were obtained in a purified form by means of gel chromatography on Sephadex G-100 as well as by zonal ultracentrifugation followed by gel chromatography. The activity is localized in the granule fraction of leucocytes (15 000 X g, 20 min) and shows a sharp pH optimum at pH 5.25. As judged from the elution profile obtained by gel chromatography, two proteins are likely to contribute to the hydrolysis of glycerol trioleate. The approximate molecular weights of the two enzymes are 74 100 and 60 300, respectively. The activity is reduced in the presence of NaCl, KCl, CaCl2 as well as of p-hydroxymercuribenzoate. The enzymes are stable at -25 degrees C but loose about 50% of their activity within 48 h at 4 degrees C.

High-dose melphalan, etoposide, total-body irradiation, and autologous stem-cell reconstitution as consolidation therapy for high-risk Ewing's sarcoma does not improve prognosis.

PURPOSE: To determine whether consolidation therapy with high-dose melphalan, etoposide, and total-body irradiation (TBI) with autologous stem-cell support would improve the prognosis for patients with newly diagnosed metastatic Ewing's sarcoma (ES). PATIENTS AND METHODS: Thirty-two eligible patients with newly diagnosed ES metastatic to bone and/or bone marrow were enrolled onto this study. Treatment was initially comprised of five cycles of induction chemotherapy (cyclophosphamide, doxorubicin, and vincristine alternating with ifosfamide and etoposide) and local control. Peripheral-blood stem-cell collection was performed after the second cycle of chemotherapy, with delay if the bone marrow was persistently involved. If patients had a good response to initial therapy, they proceeded to consolidation therapy with melphalan, etoposide, TBI, and stem-cell support. RESULTS: Of the 32 eligible patients, 23 proceeded to high-dose therapy consolidation. Of the nine patients who did not proceed to consolidation, four were secondary to progressive disease and two were secondary to toxicity. Three patients died from toxicity during the high-dose phase of the therapy. The majority of the patients who underwent high-dose consolidation therapy experienced relapse and died with progressive disease. Two-year event-free survival (EFS) for all eligible patients is 20%. The 2-year post-stem-cell reconstitution EFS for the subset of 23 patients who received consolidation therapy is 24%. Analysis of peripheral-blood stem-cell collections by molecular techniques for minimal residual disease showed contamination of at least some samples by tumor cells in all three patients with available data. CONCLUSION: Consolidation with high-dose melphalan, etoposide, TBI, and autologous stem-cell support failed to improve the probability of EFS in this cohort of patients with newly diagnosed metastatic ES.

Prevention of perinatal morbidity by tight metabolic control in gestational diabetes mellitus.

In a prospective controlled trial, we studied the effect of tight metabolic control on the outcomes of 102 gestational diabetes mellitus (GDM) pregnancies compared with outcomes of 102 matched nondiabetic control pregnancies. Women with GDM were treated to achieve and maintain a blood glucose concentration of less than 130 mg/dl at 1 h after breakfast. Treatment consisted of a diet low in oligosaccharides and fat and, if necessary, once daily insulin. By the end of gestation, 88 of the 102 women with GDM received insulin at a mean dose of 18 U/day. Duration of insulin therapy ranged from 3 to 32 wk with a median of 11 wk. Perinatal outcome of GDM pregnancies under this management equaled that of control pregnancies. The full spectrum of excess morbidity from GDM was prevented, and normal distribution of birth weight and normal rates of macrosomia, dystrophy, hypoglycemia, hypocalcemia, hyperbilirubinemia, fetal acidosis, and low Apgar scores were achieved. No mortality was observed. In addition to the two main study groups, we also studied a third group of 24 women with GDM whose treatment lasted less than or equal to 5 wk due to late diagnosis. This suboptimally treated group demonstrated a significant (P less than .05) increase of macrosomia and umbilical artery acidosis compared with the well-treated GDM group. The study reported herein demonstrates that excess mortality and morbidity typically observed in GDM can be prevented by early institution of tight metabolic control, which required insulin in 86% of our patients.

Organization of anterogradely labeled spinocervical tract terminations in the lateral cervical nucleus of the cat.

The anterograde transport of horseradish peroxidase following injections into the cervical, thoracic, or lumbosacral spinal cord was used to examine the organization of spinocervical tract terminations in the lateral cervical nucleus (LCN) of the cat. A somatotopic organization of the labeling originating from different spinal levels was observed in the mediolateral dimension. Cervical labeling generally occurred in the ventromedial portion and lumbosacral labeling in the dorsolateral portion of the LCN. Thoracic labeling occurred both in the middle and the most lateral edge of the nucleus. In all cases, labeling was distributed over most of the rostrocaudal extent of the LCN. In addition, distinct patches of labeling were present in the medialmost portion of the nucleus, regardless of the spinal level injected. These observations corroborate the topographical organization of the LCN described previously on the basis of physiological and retrograde labeling data, and support the identification of the medialmost part of the LCN as a distinct portion of the nucleus. Terminal labeling in the LCN always occurred in multiple, longitudinally distributed fields. The afferent input to each terminal field coursed in separate, loose bundles of fibers that descended from the superficial dorsolateral funiculus. Large injections resulted in more extensive, overlapping terminal fields. These observations indicate that collateral projections result in several discrete representations of a given portion of the skin over the longitudinal extent of the LCN, but that topographical relationships are longitudinally maintained. It is suggested that these multiple terminal fields are the anatomical correlate of the functionally selective convergence of spinocervical tract terminations, that has previously been postulated on physiological grounds to explain the generation of LCN receptive fields with homogenous receptor input within a somatotopic framework.

Lack of correlation between serum cholesterol levels, lymphocyte plasma membrane fluidity and mitogen responsiveness in young and aged chickens.

Chickens were studied in an attempt to demonstrate correlations between serum lipid levels and peripheral blood lymphocyte (PBL) plasma membrane fluidity and mitogen responsiveness: (a) in the laying hen; (b) during aging; and (c) following dietary manipulation of serum cholesterol of young and aged chickens. The membrane fluidity of PBL from laying hens was significantly greater than that of immature birds. However, no direct correlation was found between serum lipid levels, nor the serum free cholesterol/phospholipid (FC/Pl) mole composition and PBL membrane fluidity in any of the age-groups tested. Likewise, no correlation was found either between serum FC/Pl mole ratio or membrane fluidity and mitogen responsiveness of PBL from birds up to 5 years of age nor was there any evidence for a decline in mitogen responsiveness up to this age. Supplementation of diets with 1% cholesterol induced hypercholesterolemia, mainly in the very low density lipoprotein (VLDL) fraction, but membrane fluidity and mitogen responsiveness remained unaffected.

Comparison of the effects of halofenate (MK-185) and clofibrate on plasma lipid and uric acid concentration in hyperlipoproteinemic patients.

The plasma lipid and serum uric acid lowering effect of halofenate (MK-185, 1 g/day) was compared with the action of clofibrate (2 g/day) in a double-blind 1-yr study in 23 patients with Type 2, 3, 4, and 5 hyperlipoproteinemia. It could be demonstrated that clofibrate decreased the plasma cholesterol concentration significantly to 75% and the triglyceride concentration to 49% of the placebo period level. Halofenate produced no consistent effect on plasma cholesterol but ther was an average reduction of the plasma triglyceride concentration to 84%, which was, however, not significant. If only the Type 4 patients were taken into account, a mean significant decrease to 47% of the triglyceride concentration was observed during the second 24-week period of treatment. In contrast, halofenate lowered the serum uric acid concentration significatnly to 77% of the placebo period level, whereas the decreasing action of clofibrate was weaker (88%) and of lesser significance.

Virtual simulation: initial clinical results.

We have developed a graphics-based three-dimensional treatment design system that permits the physician to easily understand which anatomy will be treated for any arbitrary beam orientation. Our implementation of this system differs from others in that the software (the Virtual Simulator) simulates the full functionality of a (physical) radiation therapy simulator allowing it to be easily used by physicians. The details of the of our initial clinical experience with virtual simulation are presented in this paper. Virtual simulation was attempted in 71 patients and completed in 65. In 41/71 patients (58%), the beam orientations chosen differed significantly from those traditionally used in our department. Although virtual simulation lead to traditional radiation portals in the remaining patients, in 23/71 (32%) secondary blocking was designed which was different from that which would have been conventionally employed. Thus, overall, virtual simulation lead to treatment changes in 64/71 (90%) of the patients in whom it was attempted. In 78% of evaluable patients the treatment designed with virtual simulation could be implemented on the physical simulator with a precision of +/- 5 mm (+/- 3 mm for brain and head and neck). Thus virtual simulation allowed both accurate planning and execution of treatment plans that would be difficult to achieve with conventional methods.

A comparison of postoperative techniques for carcinomas of the larynx and hypopharynx using 3-D dose distributions.

If a head and neck cancer originates low in the neck with a primary site below the shoulders, a technical challenge to the radiation oncologist exists in that the entire neck needs treatment while avoiding overlap of multiple fields on the spinal cord. No standard solution to this problem exists. We have developed a 3-D treatment planning tool that can be used to develop and compare 3-D treatment plans and dose distributions. Using this tool, we have studied the following techniques for the postoperative treatment of carcinomas of the larynx and hypopharynx, tumors that often embody the problems discussed above: (a) the mini-mantle technique used at the Massachussetts General Hospital, (b) a 3-field technique used at the University of Florida at Gainesville (UF 3-field), (c) a 3-field technique used at our institution and at many others (standard 3-field), and (d) the kicked out lateral technique used at our institution and at others. The 3-D dose distributions from these plans are compared. With 100% delivered just anterior to the vertebral body at mid-neck, the mini-mantle technique results in large 120% hot spots laterally and anteriorly in the neck. Near the mastoid tips, however, the dose falls to 100%. The upper neck nodes may be underdosed since this is 20% cooler than the lateral-anterior neck dose (where a large 120% hot spot exists). The spinal cord is adequately blocked. The two 3-field techniques result in small hot spots at the junction of the lateral and anterior fields. Because different methods are used to prevent overlap at the spinal cord, these hot spots occur anteriorly in the standard 3-field technique and laterally in the UF 3-field technique. The spinal cord block results in untreated neck tissue which can be supplemented with electrons in the standard 3-field technique, but is left untreated in the UF 3-field technique. Both techniques result in a generous length of spinal cord which does not receive full dose. The kicked out lateral technique treats the entire neck and reconstructed pharynx without matching fields at midneck. The upper mid mediastinum is underdosed 10-20% despite being within the posterior inferior portion of the beam. This could be minimized by using a tissue compensator. Unless there is significant subglottic extension or significant risk of disease in the upper mediastinum, we favor treating these malignancies with the kicked out lateral technique, which avoids the problem of junctioning lateral and anterior fields and provides a fairly homogeneous dose distribution.

Ewing's sarcoma: surgical resection as a prognostic factor.

A retrospective review of 46 cases of Ewing's (43) and extraosseous Ewing's (3) sarcoma was performed to examine for prognostic factors. Follow-up ranged from 27 to 135 months with a mean of 77.6 months, 86% greater than 36 months. Nine (20%) patients presented with distant metastases, 98% received multiagent chemotherapy, and 98% received radiation therapy. Overall actuarial survival and local control at 5 years were .52 +/- .08 and .78 +/- .07, respectively. The freedom from relapse or treatment related mortality at 5 years was .46 +/- .08. In 12 (26%) patients, surgical resection of the involved bone or soft tissue was part of the initial treatment plan. Ninety-two percent (11/12) of these patients also received radiation therapy. In addition to surgical resection, tumor size (less than 500 cc vs. greater than or equal to 500 cc), primary site (central vs. other), and stage were also analyzed for prognostic significance, and where appropriate, were included in Cox multivariate analyses. Considering all patients, the 5-year actuarial survival was .92 +/- .08 vs. .37 +/- .09 for patients receiving and not receiving surgical resection, respectively (p = .001 by logrank, p = .02 by Cox). To make the groups more comparable, 8 patients with local failure and 5 patients with non-evaluable primary sites were excluded. After these exclusions, the presence or absence of surgical resection had decreased significance: .92 +/- .08 vs. .59 +/- .11, respectively; p = .01 by logrank, p = .07 by Cox. Only primary site remained statistically significant: .86 +/- .08 for noncentral sites vs. .38 +/- .16 for central sites, p less than .0002 by logrank, p = .0004 by Cox. Surgical resection when added to local irradiation has prognostic significance in this retrospective review. The reason for this is not clear, but may be related to a decrease in local failure after resection.

The tetrad and hexad: maximum beam separation as a starting point for noncoplanar 3D treatment planning: prostate cancer as a test case.

PURPOSE: In contrast to computer optimized three-dimensional (3D) treatment planning, we have used maximally separated, noncoplanar beams as the starting point for 3D treatment planning of prostate cancer to maximize the rate of dose fall off from the target volume and minimize dose to surrounding tissues. MATERIALS AND METHODS: A planar four-field plan, a planar six-field plan, a tetrad plan, and a hexad plan are analyzed using a 3D treatment planning system which is capable of displaying real-time 3D dose distributions within volume reconstructed data sets (VISTAnet--an extension of the virtual simulator). The tetrad plan is based on the methane molecule and the hexad plan has a minimum separation of 58 degrees on beam entrance. All fields are conformal. The irradiated volume equals the clinical target volume plus a 1 cm margin. Competing plans are compared using cumulative dose-volume histograms and normal tissue complication probabilities. RESULTS: The crossover point, the isodose surface that conforms more to the beams than the target, is introduced and described. The hexad and tetrad plans result in tighter dose distributions when compared to the planar plans with the same number of beams. The tetrad plan treats a volume less than or equal to the planar six-field plan at isodose surfaces above 18% except between 37% and 44% where the tetrad volume is slightly larger. As expected from integral dose considerations, the amount of normal tissue receiving some radiation increases, but the amount receiving clinically significant amounts of radiation decreases as the number of beams increase. The plan involving the largest number of noncoplanar beams results in the tightest isodose distribution. Analysis of rectal and bladder cumulative dose volume histograms does not reveal a clearly superior plan based on normal tissue complication probabilities. CONCLUSIONS: Using basic principles of solid geometry, maximally separated beams without significant overlap on exit or entrance can be designed which minimize clinically significant dose to surrounding tissues and tighten the isodose distribution around the target volume. The emphasis of this treatment plan optimization is geometric in contrast to methods using computer optimization or artificial intelligence.