bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular cloning and sequence ofSparus aurataskeletal myosin light chains expressed in white muscle: developmental expression and thyroid regulation
Authors: Moutou Katerina A. , Canario Adelino V. M. , Mamuris Zissis , Power Deborah M. 
Published: April 2021

SUMMARYTwo full-length cDNA clones encoding the skeletal myosin light chain 2 (MLC2; 1452bp) and myosin light chain 3 (MLC3; 972bp) were isolated from a cDNA library prepared from gilthead sea bream Sparus aurata larvae. The MLC2 cDNA encoded a predicted protein of 170 residues that was 79% identical to rabbit MLC2 over the entire length and 87% identical within the Ca2+-binding region. The deduced amino acid sequence of MLC3 was 153 residues in length and was 91% and 69% identical to the zebrafish and rabbit MLC3, respectively. Northern blot analysis revealed that in adults both transcripts were expressed in fast white muscle only. MLC2 appeared earlier in development: MLC2 transcripts were detectable from the beginning of segmentation, whereas MLC3 transcripts did not appear until 27h post-fertilisation. At this developmental stage, a second MLC2 transcript of 0.89 kilobase-pairs was present. MLCs exhibited a different age-related pattern of response to varied thyroidal states, which were experimentally induced by the administration of 1μgg−1bodymass of thyroxine (T4) or triiodothyronine (T3), or 5ngg−1bodymass of the hypothyroidal compound thiourea; MLC3 expression was not significantly affected, whereas levels of MLC2 transcripts were significantly elevated in the white muscle only of juvenile sea bream after administration of T4. Although the mechanism of thyroidal regulation of MLC expression remains unknown, the present results suggest that different regulatory mechanisms exist for different MLCs.
Recovery periods restore mechanosensitivity to dynamically loaded bone
Authors: Robling Alexander G. , Burr David B. , Turner Charles H. 
Published: April 2021

SUMMARYBone cells are capable of sensing and responding to mechanical forces, but mechanosensitivity begins to decline soon after the stimulus is initiated. Under continued stimulation, bone is desensitized to mechanical stimuli. We sought to determine the amount of time required to restore mechanosensitivity to desensitized bone cells in vivo by manipulating the recovery time (0, 0.5, 1, 2, 4 or 8 h) allowed between four identical daily loading bouts. We also investigated the osteogenic effectiveness of shorter-term recovery periods, lasting several seconds (0.5, 3.5, 7 or 14 s), introduced between each of 36 identical daily loading cycles. Using the rat tibia four-point bending model, the right tibia of 144 adult female Sprague-Dawley rats was subjected to bending, sham bending or no loading. In the rats receiving recovery periods between loading bouts, histomorphometric measurements from the endocortical surface of the loaded and nonloaded control (left) tibiae revealed more than 100 % higher relative bone formation rates in the 8 h recovery group than in the 0 and 0.5 h recovery groups. Approximately 8 h of recovery was sufficient to restore full mechanosensitivity to the cells. In the rats allowed time to recover between load cycles, 14 s of recovery resulted in significantly higher (66–190 %) relative bone formation rates compared to any of the three shorter recovery periods. In both experiments, bone formation in the sham-bending animals was similar to that in the nonloaded control group. The results demonstrate the importance of recovery periods for (i) restoring mechanosensitivity to bone cells and (ii) maximizing the osteogenic effects of mechanical loading (exercise) regimens.
Effects of longitudinal body position and swimming speed on mechanical power of deep red muscle from skipjack tuna (Katsuwonus pelamis)
Authors: Syme Douglas A. , Shadwick Robert E. 
Published: April 2021

SUMMARY
The mechanical power output of deep, red muscle from skipjack tuna (Katsuwonus pelamis) was studied to investigate (i) whether this muscle generates maximum power during cruise swimming, (ii) how the differences in strain experienced by red muscle at different axial body locations affect its performance and (iii) how swimming speed affects muscle work and power output. Red muscle was isolated from approximately mid-way through the deep wedge that lies next to the backbone; anterior (0.44 fork lengths, ANT) and posterior (0.70 fork lengths, POST) samples were studied. Work and power were measured at 25°C using the work loop technique. Stimulus phases and durations and muscle strains (±5.5 % in ANT and ±8 % in POST locations) experienced during cruise swimming at different speeds were obtained from previous studies and used during work loop recordings. In addition, stimulus conditions that maximized work were determined. The stimulus durations and phases yielding maximum work decreased with increasing cycle frequency (analogous to tail-beat frequency), were the same at both axial locations and were almost identical to those used by the fish during swimming, indicating that the muscle produces near-maximal work under most conditions in swimming fish. While muscle in the posterior region undergoes larger strain and thus produces more mass-specific power than muscle in the anterior region, when the longitudinal distribution of red muscle mass is considered, the anterior muscles appear to contribute approximately 40 % more total power. Mechanical work per length cycle was maximal at a cycle frequency of 2–3 Hz, dropping to near zero at 15 Hz and by 20–50 % at 1 Hz. Mechanical power was maximal at a cycle frequency of 5 Hz, dropping to near zero at 15 Hz. These fish typically cruise with tail-beat frequencies of 2.8–5.2 Hz, frequencies at which power from cyclic contractions of deep red muscles was 75–100 % maximal. At any given frequency over this range, power using stimulation conditions recorded from swimming fish averaged 93.4±1.65 % at ANT locations and 88.6±2.08 % at POST locations (means ± s.e.m., N=3–6) of the maximum using optimized conditions. When cycle frequency was held constant (4 Hz) and strain amplitude was increased, work and power increased similarly in muscles from both sample sites; work and power increased 2.5-fold when strain was elevated from ±2 to ±5.5 %, but increased by only approximately 12 % when strain was raised further from ±5.5 to ±8 %. Taken together, these data suggest that red muscle fibres along the entire body are used in a similar fashion to produce near-maximal mechanical power for propulsion during normal cruise swimming. Modelling suggests that the tail-beat frequency at which power is maximal (5 Hz) is very close to that used at the predicted maximum aerobic swimming speed (5.8 Hz) in these fish.
The Effect of Lesions to the Vertical and Optic Lobes on Tactile Discrimination in Octopus
Authors: Wells M. J. , Wells J. 
Published: April 2021

ABSTRACT
Blind octopuses were trained to make tactile discriminations between the members of pairs of objects and their performance was compared with that of other blind animals having. parts of the brain removed. It was found that removal of the optic lobes, together constituting more than half of the total mass of the brain, did not affect the performance of animals in these discrimination Removal of the vertical lode, on the other hand, produced deficiencies proportiante to the amount d tissue removed; these deficiencies were mat marked in the cose of the more difIicult of the two discrimination problems used in the tests. It was possible to compensate for loss of the vertical lobe to a considerable extent by arranging trials at more frequent intervals. Animals unable to learn a tactile discrimination when trained at rate of 8 trials per day did so when trained at 40 trials per day. When animals trained at the latter rate were subjected to reversed training, thoselacking the vertical lobe re-learned in fewer trials than controls, indicating shorter persistence of the effects of pre-reversal training. It is concluded that the vertical lobe is concerned with the persistence of conditions set up in the nervous system as a result of sensory experience. It is not known whether the vertical lobe serves to increase the initial intensity of these conditions, or to delay their decay.
The Site of Impulse Initiation in Bipolar Receptor Neurons of Callinectes Sapidus L.*
Authors: Mendelson Martin 
Published: April 2021

ABSTRACT
In bipolar neurons of the P.D. organ of Callinectes sapidus the initiation of impulses at the soma requires depolarization of at least 4-5 mV. Impulses produced by mechanical stimulation of the organ arise abruptly from the resting (potential) level without prepotential, and it is impossible to demonstrate the occurrence of generator potentials of the magnitude required for spike triggering at or near the soma. Anti- and orthodromic invasion of the soma may be differentially blocked by hyperpolarization; orthodromic block often reveals a small potential that appears to result from impulse activity in the distal process of the cell. Blockade of the soma spike to leave only the electrotonic potential of the distal process results in interruption of axonal transmission in the impaled cell. It is concluded that P.D. bipolar cells originate impulses in their distal processes with subsequent conduction through the soma into the axon.
The Mechanism of Orientation of Roach, Rutilus Rutilus L. In an Odour Gradient
Authors: Hemmings C. C. 
Published: April 2021

ABSTRACT
The behaviour of individual roach was tested in a horizontal linear gradient of roach odour. Tests with a chemical model suggested that the gradient was logarithmic. The swimming speed of the fish was not directly related to odour concentration but was low when fish swam into decreasing concentration and much higher in the opposite direction. This does not support an ortho-kinesis. Turning was more frequent at the high concentration end of the gradient which the fish ‘preferred’. This is the reverse of klino-kinesis. It is suggested that orientation is by spatial and temporal comparison of intensities, that speed is related to change in stimulation and that variation in turning serves to maintain fish at high odour concentrations.
The Repetitive Responses of Isolated Axons from the Crab, Carcinus Maenas
Authors: Chapman R. A. 
Published: April 2021

ABSTRACT
A method is described that enables the electrical responses of motor axons isolated from the leg nerve of the crab Carcinus to be studied close to or at the site of imposed electrical currents, while this area is continuously bathed by physiological solution. The three classes of repetitive responses originally described by Hodgkin (1948) have occurred during the present work and additional features of these responses have been described. The results support Hodgkin’s original thesis that the development of the spike generating mechanisms determine the response frequency during a repetitive response, but a progressive lengthening of the relative refractory period occurs during this response and is considered to be the agency that causes the gradual slowing down of the response frequency, i.e. the adaption. The processes of membrane restoration (repolarization and recovery) have been shown to be sensitive to applied currents; anodal current hastening and cathodal current slowing it. These phenomena provide a basis for interpreting the change in the duration of the relative refractory period observed during the repetitive response. The differences between the form of the repetitive response in the crab axon and the predictions of the Hodgkin-Huxley equations is discussed and it seems likely that the rapid recovery of the membrane resistance during the repolarization phase of the crab axon action potential underlies this difference.
The functional significance of the haemoglobin in a marine nematode, Enoplus brevis (Bastian)
Authors: Atkinson H.J. 
Published: April 2021

ABSTRACT
An animal chamber and a simple microspectrophotometer for investigating the in vivo oxygenation of the haemoglobin of E. brevis are described.
The in vivo absorption peaks of this haemoglobin occur at similar wavelengths to those of other nematodes. Mean values, given with their corresponding standard errors, occur at 577·6 ±0·6nm, 543·6 ± 0·5 nm and 421·7 ± 1·9 nm for oxyhaemoglobin, and 555·2 ± 0·9 nm and 432·2 ± 1·3 nm for the deoxygenated pigment.
The percentage of oxyhaemoglobin in the pharynx of E. brevis decreased at external oxygen tensions of less than 20 Torr, and the pigment was completely deoxygenated at 5 Torr. Stimulation of individuals in aerated sea water for 1–2 min caused a partial deoxygenation of the haemoglobin; the pigment reloaded soon after this period of increased activity had ended. The functional significance of the haemoglobin of E. brevis is discussed.
Evaluation of C-reactive protein and hematological parameters in smokeless tobacco users: A comparative cross-sectional study
Authors: Memon Sikander Munir , Kumar Naresh , Rahman Aneela Atta Ur , Syed Binafsha Manzoor 
Published: April 2021

Objective: To investigate the changes in levels of C-reactive protein (CRP) and hematological parameters among smokeless tobacco (SLT) users.
Methods: A comparative cross-sectional study was conducted at the community level in the coastal districts of Sindh province namely Badin, Thatta, and Sujawal from January 2017 to December 2019. The CRP and hematological parameters were evaluated by well-established methods among SLT and non-SLT users.
Results: There was a statistically significant difference between SLT users (mean CRP = 0.77) versus non-users (mean CRP = 0.18), p = <0.001. Among hematological parameters, white blood cells (SLT users median = 7.85 versus non-SLT users median = 8.50, p = 0.004), monocytes (SLT users median = 6.00 versus non-SLT users median = 6.00, p = 0.001) and erythrocyte sedimentation rate (SLT users median = 15.00 versus non-SLT users median = 10.00, p = 0.006) showed statistically significant difference.
Conclusions: Significantly elevated CRP was observed in SLT users similarly hematological parameters also showed changes. WBCs, monocytes and ESR were significantly deranged among SLT users. Further studies looking into long term effects of these changes would be helpful.
doi: https://doi.org/10.12669/pjms.37.4.3841
How to cite this:Memon SM, Kumar N, Atta-Ur-Rahman A, Syed BM. Evaluation of C-reactive protein and hematological parameters in smokeless tobacco users: A comparative cross-sectional study. Pak J Med Sci. 2021;37(4):983-987. doi: https://doi.org/10.12669/pjms.37.4.3841
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The effect of morning versus evening administration of empagliflozin on its pharmacokinetics and pharmacodynamics characteristics in healthy adults: a two-way crossover, non-randomised trial
Authors: ElDash Rana M. , Raslan Mohamed A. , Shaheen Sara M. , Sabri Nagwa Ali 
Published: April 2021

Background: Empagliflozin is an SGLT2 inhibitor approved for use in patients with diabetes mellitus type 2 (DMT2) with or without other cardiovascular disease. Empagliflozin is taken once daily without rationale on the optimal timing for administration. This study aimed to determine the chronopharmacological effects of morning vs evening administration of empagliflozin (10 mg) in healthy Egyptian adults, by investigating the pharmacokinetics and pharmacodynamics parameters of empagliflozin depending on the intake time. Methods: An open label, sequential, two‐way crossover trial comprised of two periods with a washout period of 7 days. All participants received a single oral dose of empagliflozin (JARDIANCE ®; 10 mg film coated tablet) in the evening, and after a seven-day washout period, the morning. Pharmacokinetics parameters (primary endpoints: tmax (h), Cmax (ng/ml), AUC 0-t (ng.h/ml); secondary endpoints: AUC 0 to ∞(ng.h/ml)) were assessed. Method validation was done prior to injection in LC/MS/MS and samples were processed by Liquid-Liquid extraction. The pharmacodynamic profile (UGE 0-24) was determined after method validation (glucose hexokinase method). Results: Tmax increased by 35% in the evening phase compared to the morning phase, while Cmax decreased by -6.5% in the evening dose compared to the morning dose. Additionally, AUC0 to ∞ increased in the evening phase by 8.25% compared to the morning phase. The mean cumulative amount of glucose excreted (UGE (0-24)) increased by 43% in the evening dose compared to the morning dose Conclusion: Despite the difference in pharmacokinetics parameters between evening and morning doses, Cmax, AUC0-t, AUC 0-∞, didn’t differ on the bioequivalence level. In addition, as UGE (0-24) didn’t statistically differ, thus, we can conclude that there is no statistical significance between the morning and evening doses. Trial registration: Clinal Trials.gov, ID: NCT03895229 (registered on 29th March 2019).
Tantala Kerr nonlinear integrated photonics
Authors: Jung Hojoong , Yu Su-Peng , Carlson David R. , Drake Tara E. , Briles Travis C. , Papp Scott B. 
Published: April 2021

Integrated photonics plays a central role in modern science and technology, enabling experiments from nonlinear science to quantum information, ultraprecise measurements and sensing, and advanced applications such as data communication and signal processing. Optical materials with favorable properties are essential for nanofabrication of integrated photonics devices. Here we describe a material for integrated nonlinear photonics, tantalum pentoxide (

T
a

2

O

5

, hereafter tantala), which offers low intrinsic material stress, low optical loss, and efficient access to Kerr nonlinear processes. We utilize

>

800

n
m

thick tantala films deposited via ion beam sputtering on oxidized silicon wafers. The tantala films contain a low residual tensile stress of 38 MPa, and they offer a Kerr index of

n
2

=
6.2
±
2.3
×

10

−
19

m

2

/

W

, which is approximately a factor of 3 higher than silicon nitride. We fabricate integrated nonlinear resonators and waveguides without the cracking challenges that are prevalent in stoichiometric silicon nitride. The tantala resonators feature an optical quality factor up to

3.8
×

10
6

, which enables us to generate ultrabroad bandwidth Kerr soliton frequency combs with low threshold power. Moreover, we characterize tantala waveguides by supercontinuum generation from low-energy, ultrafast seed pulses. These demonstrations characterize future application directions with tantala integrated nonlinear photonics.
Comb operation in terahertz quantum cascade ring lasers
Authors: Jaidl M. , Opačak N. , Kainz M. A. , Schönhuber S. , Theiner D. , Limbacher B. , Beiser M. , Giparakis M. , Andrews A. M. , Strasser G. , Schwarz B. , Darmo J. , Unterrainer K. 
Published: April 2021

Ring resonators are an interesting alternative cavity solution to the commonly used ridge-type waveguide for terahertz (THz) quantum cascade lasers. They either support a standing-wave pattern showing spatial hole burning if there are defects implemented or a traveling mode in a defect-free cavity. Here, we report on ring-shaped THz quantum cascade lasers emitting between 3.2 and 4.1 THz operating in four different emission regimes. The presence of defects in the cavities force the THz quantum cascade laser into a standing-wave pattern. The measurements show a complex behavior highlighting the effect of strong confinement and the optical nonlinearities leading to the generation of a harmonic state, as well as to a fundamental comb, exhibiting over 30 equidistant modes and covering a bandwidth of 622 GHz. The results are explained by numerical calculations based on the Maxwell–Bloch formalism, including the linewidth enhancement factor and reflection points. The compact geometry and high output power (4 mW detected) make these devices extremely appealing for on-chip frequency comb applications in the terahertz region.
Tunable photon blockade with a single atom in a cavity under electromagnetically induced transparency
Authors: Tang Jing , Deng Yuangang , Lee Chaohong 
Published: April 2021

We present an experimental proposal to achieve a strong photon blockade by employing electromagnetically induced transparency (EIT) with a single alkaline-earth-metal atom trapped in an optical cavity. In the presence of optical Stark shift, both the second-order correlation function and cavity transmission exhibit asymmetric structures between the red and blue sidebands of the cavity. For a weak control field, the photon quantum statistics for the coherent transparency window (i.e., atomic quasi-dark-state resonance) are insensitive to the Stark shift, which should also be immune to the spontaneous emission of the excited state by taking advantage of the intrinsic dark-state polariton of EIT. Interestingly, by exploiting the interplay between the Stark shift and control field, the strong photon blockade at atomic quasi-dark-state resonance has an optimal second-order correlation function

g

(
2
)

(
0
)
∼

10

−
4

and a high cavity transmission simultaneously. The underlying physical mechanism is ascribed to the Stark shift enhanced spectrum anharmonicity and the EIT hosted strong nonlinearity with loss-insensitive atomic quasi-dark-state resonance, which is essentially different from the conventional proposal with emerging Kerr nonlinearity in cavity-EIT. Our results reveal a new strategy to realize high-quality single photon sources, which could open up a new avenue for engineering nonclassical quantum states in cavity quantum electrodynamics.
PIC-integrable, uniformly tensile-strained Ge-on-insulator photodiodes enabled by recessed SiNx stressor
Authors: Lin Yiding , Ma Danhao , Hong Lee Kwang , Wen Rui-Tao , Syaranamual Govindo , Kimerling Lionel C. , Seng Tan Chuan , Michel Jurgen 
Published: April 2021

Mechanical strain engineering has been promising for many integrated photonic applications. However, for the engineering of a material electronic bandgap, a trade-off exists between the strain uniformity and the integration compatibility with photonic-integrated circuits (PICs). Herein, we adopted a straightforward recess-type design of a silicon nitride (

SiN

x

) stressor to achieve a uniform strain with enhanced magnitude in the material of interest on PICs. Normal-incidence, uniformly 0.56% tensile strained germanium (Ge)-on-insulator (GOI) metal-semiconductor-metal photodiodes were demonstrated, using the recessed stressor with 750 MPa tensile stress. The device exhibits a responsivity of

1.84
±
0.15

A
/
W

at 1550 nm. The extracted Ge absorption coefficient is enhanced by

∼
3.2
×

to

8340

cm

−
1

at 1612 nm and is superior to that of

In

0.53

Ga

0.47

As

up to 1630 nm limited by the measurement spectrum. Compared with the nonrecess strained device, additional absorption coefficient improvement of 10%–20% in the

C

-band and 40%–60% in the

L

-band was observed. This work facilitates the recess-strained GOI photodiodes for free-space PIC applications and paves the way for various (e.g., Ge, GeSn or III-V based) uniformly strained photonic devices on PICs.