19 research outputs found
Causes of variation in intrinsic ankle stiffness and the consequences for standing
Previous studies have shown that the intrinsic mechanical stiffness of the ankles is less than necessary to fully stabilize the body in the upright position (Loram and Lakie, 2002a; Morasso and Schieppati, 1999; Morasso and Sanguineti, 2002; Casadio et al., 2005). Following these studies, research about the controlling mechanisms of standing (the maintenance of an upright posture by a combination of intrinsic and active mechanisms) has developed considerably (Lakie et al., 2003; Loram et al., 2005a,b, 2011; Masani et al., 2006; Maurer and Peterka, 2005; Peterka, 2002). However, very little attention was given to the intrinsic mechanisms themselves. Here I tackled this issue by manipulating the ankle (and its surrounding tissues) in various ways. The objective was to investigate ankle stiffness dependency on mechanical properties that are particular to muscles and tendons. Within-individual differences were confirmed in various conditions. I have shown that in standing, intrinsic ankle stiffness is affected by movement amplitude and history of movement, as well as active ankle torque and passive tendon stretch. I have found no dependency of ankle stiffness on localized cooling. With regards to the effect that differences in intrinsic ankle stiffness may cause to standing sway, a between-individual analysis showed an inverse correlation between ankle stiffness and sway magnitude
Litter reduction during beach closure in the context of the COVID-19 pandemic : quantifying the impact of users on beach litter generation
This study aimed to quantify marine litter before and during the COVID pandemic found on urban touristic beaches closed to beachgoer access in northeastern Brazil. Litter identification and quantification was conducted during April, June, and August 2019, when 3583 items were sampled, and replicated during the same months in 2020, when access to the beaches studied was prohibited and a significant reduction in the amount of litter was found, 1812 items (49% decrease). Transects were used to monitor and classify litter according to its source, namely: autochthonous (litter that was locally discarded) and allochthonous (litter from other sites and sources). All beaches were classified as "very clean" and presented a smaller amount of litter during the beach closure period. The highest total marine litter reduction between the periods studied was 83%, while au tochthonous litter in particular showed the most significant reduction, 88%. The comparison between the quantity and type of litter found in both periods showed greater specific anthropic pressure from beach users. Keywords: beach management. Coastal tourism. Environmental quality. Solid waste management
Ultrasonic Generation of Pulsatile and Sequential Therapeutic Delivery Profiles from Calcium-Crosslinked Alginate Hydrogels
Control over of biological processes can potentially be therapeutically regulated through localized biomolecular deliveries. While implantable hydrogels can provide localized therapeutic deliveries, they do not traditionally provide the temporally complex therapeutic delivery profiles required to regulate complex biological processes. Ionically crosslinked alginate hydrogels have been shown to release encapsulated payloads in response to a remotely applied ultrasonic stimulus, thus potentially enabling more temporally complex therapeutic delivery profiles. However, thorough characterizations of how different types of therapeutic payloads are retained and ultrasonically released need to be performed. Additionally, the impact of potentially disruptive ultrasonic stimulations on hydrogel structure and temperature need to be characterized to better understand what range of ultrasonic signals can be used to trigger release. To perform these characterizations, calcium-crosslinked alginate hydrogels were loaded with various model macromolecules (dextrans), chemotherapeutics, and protein signaling factors and exposed to a variety of single-pulse and multi-pulse ultrasonic signals at various amplitudes and durations. In response to single-pulsed ultrasonic exposures, quantifications of molecular release, degree of gel erosion, and increase in hydrogel temperature revealed that the ultrasonic stimulations required for statistically significant therapeutic deliveries often eroded and heated the gels to unacceptable levels. However, multi-pulse ultrasonic exposures were shown to achieve significant amounts of therapeutic release while keeping gel erosion and temperature increase at modest levels. Finally, experiments were performed demonstrating that ultrasonic stimulation could be used to generate drug release profiles shown to have potential therapeutic benefits (e.g., pulsatile and sequential anticancer delivery profiles). This work underscores the potential of using ultrasonically responsive polymeric hydrogels for providing on-demand control over more complex therapeutic deliver profiles and enhancing drug delivery strategies in cancer therapies and beyond
Pulsatile Chemotherapeutic Delivery Profiles Using Magnetically Responsive Hydrogels
Pulsatile
chemotherapeutic delivery profiles may provide a number
advantages by maximizing the anticancer toxicity of chemotherapeutics,
reducing off-target side effects, and combating adaptive resistance.
While these temporally dynamic deliveries have shown some promise,
they have yet to be clinically deployed from implantable hydrogels,
whose localized deliveries could further enhance therapeutic outcomes.
Here, several pulsatile chemotherapeutic delivery profiles were tested
on melanoma cell survival in vitro and compared to constant (flatline)
delivery profiles of the same integrated dose. Results indicated that
pulsatile delivery profiles were more efficient at killing melanoma
cells than flatline deliveries. Furthermore, results suggested that
parameters like the duration of drug “on” periods (pulse
width), delivery rates during those periods (pulse heights), and the
number/frequency of pulses could be used to optimize delivery profiles.
Optimization of pulsatile profiles at tumor sites in vivo would require
hydrogel materials capable of producing a wide variety of pulsatile
profiles (e.g., of different pulse heights, pulse widths, and pulse
numbers). This work goes on to demonstrate that magnetically responsive,
biphasic ferrogels are capable of producing pulsatile mitoxantrone
delivery profiles similar to those tested in vitro. Pulse parameters
such as the timing and rate of delivery during “on”
periods could be remotely regulated through the use of simple, hand-held
magnets. The timing of pulses was controlled simply by deciding when
and for how long to magnetically stimulate. The rate of release during
pulse “on” periods was a function of the magnetic stimulation
frequency. These findings add to the growing evidence that pulsatile
chemotherapeutic delivery profiles may be therapeutically beneficial
and suggest that magnetically responsive hydrogels could provide useful
tools for optimizing and clinically deploying pulsatile chemotherapeutic
delivery profiles
Pulsatile Chemotherapeutic Delivery Profiles Using Magnetically Responsive Hydrogels
Pulsatile
chemotherapeutic delivery profiles may provide a number
advantages by maximizing the anticancer toxicity of chemotherapeutics,
reducing off-target side effects, and combating adaptive resistance.
While these temporally dynamic deliveries have shown some promise,
they have yet to be clinically deployed from implantable hydrogels,
whose localized deliveries could further enhance therapeutic outcomes.
Here, several pulsatile chemotherapeutic delivery profiles were tested
on melanoma cell survival in vitro and compared to constant (flatline)
delivery profiles of the same integrated dose. Results indicated that
pulsatile delivery profiles were more efficient at killing melanoma
cells than flatline deliveries. Furthermore, results suggested that
parameters like the duration of drug “on” periods (pulse
width), delivery rates during those periods (pulse heights), and the
number/frequency of pulses could be used to optimize delivery profiles.
Optimization of pulsatile profiles at tumor sites in vivo would require
hydrogel materials capable of producing a wide variety of pulsatile
profiles (e.g., of different pulse heights, pulse widths, and pulse
numbers). This work goes on to demonstrate that magnetically responsive,
biphasic ferrogels are capable of producing pulsatile mitoxantrone
delivery profiles similar to those tested in vitro. Pulse parameters
such as the timing and rate of delivery during “on”
periods could be remotely regulated through the use of simple, hand-held
magnets. The timing of pulses was controlled simply by deciding when
and for how long to magnetically stimulate. The rate of release during
pulse “on” periods was a function of the magnetic stimulation
frequency. These findings add to the growing evidence that pulsatile
chemotherapeutic delivery profiles may be therapeutically beneficial
and suggest that magnetically responsive hydrogels could provide useful
tools for optimizing and clinically deploying pulsatile chemotherapeutic
delivery profiles
Pulsatile Chemotherapeutic Delivery Profiles Using Magnetically Responsive Hydrogels
Pulsatile
chemotherapeutic delivery profiles may provide a number
advantages by maximizing the anticancer toxicity of chemotherapeutics,
reducing off-target side effects, and combating adaptive resistance.
While these temporally dynamic deliveries have shown some promise,
they have yet to be clinically deployed from implantable hydrogels,
whose localized deliveries could further enhance therapeutic outcomes.
Here, several pulsatile chemotherapeutic delivery profiles were tested
on melanoma cell survival in vitro and compared to constant (flatline)
delivery profiles of the same integrated dose. Results indicated that
pulsatile delivery profiles were more efficient at killing melanoma
cells than flatline deliveries. Furthermore, results suggested that
parameters like the duration of drug “on” periods (pulse
width), delivery rates during those periods (pulse heights), and the
number/frequency of pulses could be used to optimize delivery profiles.
Optimization of pulsatile profiles at tumor sites in vivo would require
hydrogel materials capable of producing a wide variety of pulsatile
profiles (e.g., of different pulse heights, pulse widths, and pulse
numbers). This work goes on to demonstrate that magnetically responsive,
biphasic ferrogels are capable of producing pulsatile mitoxantrone
delivery profiles similar to those tested in vitro. Pulse parameters
such as the timing and rate of delivery during “on”
periods could be remotely regulated through the use of simple, hand-held
magnets. The timing of pulses was controlled simply by deciding when
and for how long to magnetically stimulate. The rate of release during
pulse “on” periods was a function of the magnetic stimulation
frequency. These findings add to the growing evidence that pulsatile
chemotherapeutic delivery profiles may be therapeutically beneficial
and suggest that magnetically responsive hydrogels could provide useful
tools for optimizing and clinically deploying pulsatile chemotherapeutic
delivery profiles
Pulsatile Chemotherapeutic Delivery Profiles Using Magnetically Responsive Hydrogels
Pulsatile
chemotherapeutic delivery profiles may provide a number
advantages by maximizing the anticancer toxicity of chemotherapeutics,
reducing off-target side effects, and combating adaptive resistance.
While these temporally dynamic deliveries have shown some promise,
they have yet to be clinically deployed from implantable hydrogels,
whose localized deliveries could further enhance therapeutic outcomes.
Here, several pulsatile chemotherapeutic delivery profiles were tested
on melanoma cell survival in vitro and compared to constant (flatline)
delivery profiles of the same integrated dose. Results indicated that
pulsatile delivery profiles were more efficient at killing melanoma
cells than flatline deliveries. Furthermore, results suggested that
parameters like the duration of drug “on” periods (pulse
width), delivery rates during those periods (pulse heights), and the
number/frequency of pulses could be used to optimize delivery profiles.
Optimization of pulsatile profiles at tumor sites in vivo would require
hydrogel materials capable of producing a wide variety of pulsatile
profiles (e.g., of different pulse heights, pulse widths, and pulse
numbers). This work goes on to demonstrate that magnetically responsive,
biphasic ferrogels are capable of producing pulsatile mitoxantrone
delivery profiles similar to those tested in vitro. Pulse parameters
such as the timing and rate of delivery during “on”
periods could be remotely regulated through the use of simple, hand-held
magnets. The timing of pulses was controlled simply by deciding when
and for how long to magnetically stimulate. The rate of release during
pulse “on” periods was a function of the magnetic stimulation
frequency. These findings add to the growing evidence that pulsatile
chemotherapeutic delivery profiles may be therapeutically beneficial
and suggest that magnetically responsive hydrogels could provide useful
tools for optimizing and clinically deploying pulsatile chemotherapeutic
delivery profiles
Recommended from our members
International collaboration for assessing unmet needs of cancer survivors and family caregivers: Lens of healthcare professionals
Cancer patients and their family caregivers have reported various needs that are not met. Recognition of the unmet needs by healthcare professionals may be a first step to adequately and systematically addressing them. Thus, the International Psycho-Oncology Society Survivorship Online Survey was developed to measure healthcare professionals' evaluation about the unmet needs of their patients and family caregivers around the globe.
The survey was developed in English and translated to additional 14 different languages. The survey was distributed on the web-based REDCap application to over 50 psycho-oncology societies and their networking platforms as well as social media and to authors who have published in psycho-oncology journals globally.
A total of 1472 participants from 36 countries at least partially completed the survey. Healthcare professionals evaluated needs for managing one's emotional distress and patients' medical care and symptoms as the most common concerns for both patients and their family caregivers across all patient age groups. Less than two-thirds of the participating healthcare professionals reported that their institution had services or programs to address the needs of the patients or caregivers.
Findings suggest several directions for further analyses to provide more specific information that would be readily translated into clinical practices, research, and policy aimed to enhance the quality of life of cancer patients, survivors, and family caregivers around the globe. In addition, this collaborative effort also hints at the importance of establishing international networks to promote equity in care for people touched by cancer worldwide