In Vivo Total Dose Analysis in Mice for BNCT Trial TRIGA Kartini Research Reactor Based Using PHITS

Boron neutron capture therapy (BNCT) is an effective radiotherapy modality to kill cancer. BNCT can selectively kill cancer cells without damaging the healthy tissue around it by using alpha particle and lithium ion from the reaction of 10B(n,α)7Li. These particles have a track of more or less 5 to 9 μm which is the same as the cell diameter. In order to support the development of BNCT in Indonesia an in vivo simulation is performed in a simple mouse geometry containing a 4T1 breast cancer characteristic treated with BNCT using PHITS program. The Neutron source that was used in this simulation was based on TRIGA Kartini Research Reactor. The boron compound concentration in the tumor was varied from 20 ppm up to 90 ppm, and then the total dose was calculated in the mice. Total dose that the tumor received was 0.0161, 0.0168, 0.0175, 0.0182, 0.0185, 0.0188, 0.019, and 0.0191 Gy-Eq/s, respectively and the irradiation time to reach 50 Gy was 51, 50, 48, 46, 45, 45, 44, 44, 40 minutes respectively. This shows that the higher the concentration of boron compound in the tumor the higher the dose that mice received and irradiation time was decreased with the increase of the boron compound concentration

Optogenetic Interrogation of Functional Synapse Formation by Corticospinal Tract Axons in the Injured Spinal Cord

To restore function after injury to the CNS, axons must be stimulated to extend into denervated territory and, critically, must form functional synapses with appropriate targets. We showed previously that forced overexpression of the transcription factor Sox11 increases axon growth by corticospinal tract (CST) neurons after spinal injury. However, behavioral outcomes were not improved, raising the question of whether the newly sprouted axons are able to form functional synapses. Here we developed an optogenetic strategy, paired with single-unit extracellular recordings, to assess the ability of Sox11-stimulated CST axons to functionally integrate in the circuitry of the cervical spinal cord. Initial time course experiments established the expression and function of virally expressed Channelrhodopsin (ChR2) in CST cell bodies and in axon terminals in cervical spinal cord. Pyramidotomies were performed in adult mice to deprive the left side of the spinal cord of CST input, and the right CST was treated with adeno-associated virus (AAV)–Sox11 or AAV–EBFP control, along with AAV–ChR2. As expected, Sox11 treatment caused robust midline crossing of CST axons into previously denervated left spinal cord. Clear postsynaptic responses resulted from optogenetic activation of CST terminals, demonstrating the ability of Sox11-stimulated axons to form functional synapses. Mapping of the distribution of CST-evoked spinal activity revealed overall similarity between intact and newly innervated spinal tissue. These data demonstrate the formation of functional synapses by Sox11-stimulated CST axons without significant behavioral benefit, suggesting that new synapses may be mistargeted or otherwise impaired in the ability to coordinate functional output. SIGNIFICANCE STATEMENT As continued progress is made in promoting the regeneration of CNS axons, questions of synaptic integration are increasingly prominent. Demonstrating direct synaptic integration by regenerated axons and distinguishing its function from indirect relay circuits and target field plasticity have presented technical challenges. Here we force the overexpression of Sox11 to stimulate the growth of corticospinal tract axons in the cervical spinal cord and then use specific optogenetic activation to assess their ability to directly drive postsynaptic activity in spinal cord neurons. By confirming successful synaptic integration, these data illustrate a novel optogenetic-based strategy to monitor and optimize functional reconnection by newly sprouted axons in the injured CNS

Temporal dynamics of semiconductor lasers with optical feedback

Includes bibliographical references (page 5539).We measure the temporal evolution of the intensity of an edge emitting semiconductor laser with delayed optical feedback for time spans ranging from 4.5 to 65 ns with a time resolution from 16to 230 ps, respectively. Spectrally resolved streak camera measurements show that the fast pulsing of the total intensity is a consequence of the time delay and multimode operation of the laser. We experimentally observe that the instabilities at low frequency are generated by the interaction among different modes of the laser

Temporal dynamics of semiconductor lasers with optical feedback

We measure the temporal evolution of the intensity of an edge emitting semiconductor laser with delayed optical feedback for time spans ranging from 4.5 to 65 ns with a time resolution from 16 to 230 ps, respectively. Spectrally resolved streak camera measurements show that the fast pulsing of the total intensity is a consequence of the time delay and multimode operation of the laser. We experimentally observe that the instabilities at low frequency are generated by the interaction among different modes of the laser.We acknowledge support of the European Community TMR program, the NSF Optoelectronic Computing System Center, the NSF (ECS 95-02888), CICYT Project No. TIC95-0563, and DGICYT Project No. SAB95-0674.Peer Reviewe

Can Weakness in End-Range Plantar Flexion After Achilles Tendon Repair Be Prevented?

Background: Disproportionate end-range plantar flexion weakness, decreased passive stiffness, and inability to perform a heel rise on a decline after Achilles tendon repair are thought to reflect increased tendon compliance or tendon lengthening. Since this was first noted, we have performed stronger repairs and avoided stretching into dorsiflexion for the first 12 weeks after surgery. Hypothesis: Using stronger repairs and avoiding stretching into dorsiflexion would eliminate end-range plantar flexion weakness and normalize passive stiffness. Study Design: Case series; Level of evidence, 4. Methods: Achilles repairs with epitendinous augmentation were performed on 18 patients. Plantar flexion torque, dorsiflexion range of motion (ROM), passive joint stiffness, and standing single-legged heel rise on a decline were assessed at 43 ± 24 months after surgery (range, 9 months to 8 years). Maximum isometric plantar flexion torque was measured at 20° and 10° of dorsiflexion, neutral position, and 10° and 20° of plantar flexion. Passive dorsiflexion ROM was measured with a goniometer. Passive joint stiffness was computed from the increase in passive torque from 10° to 20° of dorsiflexion. Tendon thickness was measured by use of digital calipers. Plantar flexion electromyographic (EMG) data were recorded during strength and functional tests. Analysis of variance and chi-square tests were used to assess weakness and function. Results: Marked weakness was evident on the involved side at 20° of plantar flexion (deficit, 26% ± 18%; Conclusion: The use of stronger repair techniques and attempts to limit tendon elongation by avoiding dorsiflexion stretching did not eliminate weakness in end-range plantar flexion. EMG data confirmed that end-range weakness was not due to neural inhibition. Physiological changes that alter the force transmission capability of the healing tendon may be responsible for this continued impairment. This weakness has implications for high-demand jumping and sprinting after Achilles tendon repair

Instrumentation, Field Network and Process Automation for the Cryogenic System of the LHC Test String

CERN is now setting up String 2, a full-size prototype of a regular cell of the LHC arc. It is composed of two quadrupole, six dipole magnets, and a separate cryogenic distribution line (QRL) for the supply and recovery of the cryogen. An electrical feed box (DFB), with up to 38 High Temperature Superconducting (HTS) leads, powers the magnets. About 700 sensors and actuators are distributed along four Profibus DP and two Profibus PA field buses. The process automation is handled by two controllers, running 126 Closed Control Loops (CCL). This paper describes the cryogenic control system, associated instrumentation, and their commissioning

Health care services for older people in COVID-19 pandemic times – a Nordic comparison

Objective: To explore the Nordic municipal health and care services’ ability to promote principal goals within care for older people during the COVID-19 pandemic.Design and setting: Two surveys were conducted among managers of municipal health care services for older adults in Denmark, Finland, Norway and Sweden; the first around 6 months into the pandemic (survey 1), and the second around 12 months later (survey 2). Data were analysed through descriptive statistics, and multiple regression (OLS).Subjects: 1470 (survey 1, 2020) and 745 (survey 2, 2021) managers. 32 % in home care, 51 % in nursing homes, 17 % combined. Results: In all countries the pandemic seems to have had more negative impact on eldercare services’ ability to promote an active and social life, than on the ability to promote or enhance older people’s mental and physical health. The regression analysis indicates that different factors influence the ability to promote these goals. Managers within nursing homes reported reduced ability to promote mental and physical health and an active social life to a significantly lower degree than managers of home care. The effect of three prevention strategies (lock down, testing, and/or organisational change), were explored. Organisational change (reorganize staff and practice, restrict use of substitutes) tended to impact the units’ ability to promote a social life in a positive direction, while lock down (areas, buffets etc) tended to impact both the ability to promote mental/physical health and a social life in a negative direction. Conclusion: Measures that can improve opportunities for an active and social life during a pandemic should have high priority, particularily within home-based care.Objective: To explore the Nordic municipal health and care services’ ability to promote principal goals within care for older people during the COVID-19 pandemic. Design and setting: Two surveys were conducted among managers of municipal health care services for older people in Denmark, Finland, Norway and Sweden; the first around 6 months into the pandemic (survey 1), and the second around 12 months later (survey 2). Data were analysed through descriptive statistics, and multiple regression (OLS). Subjects: 1470 (survey 1, 2020) and 745 (survey 2, 2021) managers. 32% in home care, 51% in nursing homes, 17% combined. Results: In all countries the pandemic seems to have had more negative impact on eldercare services’ ability to promote an active and social life, than on the ability to promote or enhance older people’s mental and physical health. The regression analysis indicates that different factors influence the ability to promote these goals. Managers within nursing homes reported reduced ability to promote mental and physical health and an active social life to a significantly lower degree than managers of home care. The effect of three prevention strategies (lock down, testing, and/or organisational change), were explored. Organisational change (reorganize staff and practice, restrict use of substitutes) tended to impact the units’ ability to promote a social life in a positive direction, while lock down (areas, buffets etc) tended to impact both the ability to promote mental/physical health and a social life in a negative direction. Conclusion: Measures that can improve opportunities for an active and social life during a pandemic should have high priority, particularily within home care.</p