TrialPanorama/TrialPanorama-database huggingface dataset:
Study: NCT03317977

Intervention type: BEHAVIORAL
Group type: EXPERIMENTAL
Intervention: Reach for Control
Description: In Phase 1 (weeks 1-4), the CHW conducts an initial intake and then completes a comprehensive functional analysis (FA) of behavior to determine the causes of poor asthma management for each youth regarding asthma management. In Phase 2 (weeks 5-20) is a treatment phase and consists of a combination of mandatory cognitive-behavioral skills training (CBST) modules (received by all families) and flexible CBST modules chosen and individualized based on the results of the Phase 1 FA. This includes but not limited to In-vivo Asthma Skills Training, Improving Family Communication and Behavioral Contracting. Phase 3 (weeks 21-24) involves termination planning and relapse prevention

Intervention type: BEHAVIORAL
Group type: ACTIVE_COMPARATOR
Intervention: MATCH
Description: Managing Asthma Through Case Management in Home (MATCH) is the current intervention provided by WCHAP to youth with poorly controlled asthma and their families.
Study: NCT03199625

Intervention type: BEHAVIORAL
Group type: EXPERIMENTAL
Intervention: Cognitive therapy

Intervention type: BEHAVIORAL
Group type: EXPERIMENTAL
Intervention: Behavior therapy

Intervention type: DRUG
Group type: ACTIVE_COMPARATOR
Intervention: SSRI antidepressants
Study: NCT00278434

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Zoledronate

Intervention type: OTHER
Group type: PLACEBO_COMPARATOR
Intervention: Placebo (Saline)
Study: NCT00333463

Intervention type: BEHAVIORAL
Intervention: Intervention
Description: The intervention group watched an educational video, reviewed current barriers to drop-taking and possible solutions with a study coordinator, received regular phone call reminders, and had audible and visible reminders activated on their DA devices.
Study: NCT00943540

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: raltegravir QD
Description: Raltegravir 800mg QD

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: atazanavir
Description: atazanavir

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: lamivudine (or emtricitabine)
Description: lamivudine (or emtricitabine)
Study: NCT02494258

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: CC-486
Description: The subject will continue at the same dose, frequency and schedule used for the last dose of CC-486 given in the preceding CC-486 study. Subjects are allowed to rollover after the last cycle is finished and before the new cycle begins in the parent protocol. There is a 7 day window from End of Study on the parent protocol and when the participant will start Day 1 of the rollover study.
Study: NCT02498444

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Treprostinil
Description: Administration of drug (treprostinil) vs placebo (saline) in the post-operative period

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Treprostinil
Description: Administration of drug (treprostinil) vs placebo (saline) in the post-operative period
Study: NCT00746564

Intervention type: DEVICE
Group type: EXPERIMENTAL
Intervention: SJM Confirm
Description: All patients in this study will receive the SJM Confirm device.
Study: NCT01997788

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: The intrathecal morphine injection
Description: A single injection of morphine intrathecally

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: The intravenous patient-controlled analgesia
Description: The intravenous injection of morphine using the patient-controlled analgesia machine

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: The intravenous patient-controlled analgesia
Description: The intravenous injection of morphine using the patient-controlled analgesia machine

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Demerol on demand
Description: Demerol 25 mg intravenously when pain scores more than 5.

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Demerol on demand
Description: Demerol 25 mg intravenously when pain scores more than 5.
Study: NCT00546377

Intervention type: BIOLOGICAL
Group type: EXPERIMENTAL
Intervention: filgrastim

Intervention type: BIOLOGICAL
Group type: EXPERIMENTAL
Intervention: pegfilgrastim

Intervention type: BIOLOGICAL
Group type: EXPERIMENTAL
Intervention: rituximab

Intervention type: BIOLOGICAL
Group type: EXPERIMENTAL
Intervention: sargramostim

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: cyclophosphamide
Study: NCT01367327

Intervention type: BEHAVIORAL
Group type: EXPERIMENTAL
Intervention: Loaded sit-to-stand exercise
Description: Loaded sit-to-stand exercise at home, 3 times a week for 6 weeks

Intervention type: BEHAVIORAL
Group type: ACTIVE_COMPARATOR
Intervention: Loaded sit-to-stand exercise
Description: Loaded sit-to-stand exercise at home, 3 times a week for 6 weeks

Intervention type: BEHAVIORAL
Group type: EXPERIMENTAL
Intervention: Synchronized music
Description: Synchronized music for loaded sit-to-stand exercise to guide movement
Study: NCT04637204

Intervention type: DRUG
Intervention: Cabozantinib
Description: oral therapy

Intervention type: DRUG
Intervention: Cabozantinib
Description: oral therapy

Intervention type: DRUG
Intervention: Axitinib
Description: oral therapy

Intervention type: DRUG
Intervention: Axitinib
Description: oral therapy
Study: NCT02742168

Intervention type: RADIATION
Group type: EXPERIMENTAL
Intervention: 99mTc-3PRGD2
Description: Diagnostic group：For patients in suspicion of breast cancer, single intravenous bolus injection of nearly 0.3 mCi/kg body weight of 99mTc-3PRGD2 on day one of the treatment period, whole-body planar and lesions SPECT/CT to determine the accumulation of 99mTc-3PRGD2 in the tumors and the other parts of the body.~Efficacy evaluation group：patients firstly diagnose with malignant lesions ,and prepare to chemotherapy(including neoadjuvant chemotherapy) or radiotherapy.the same dose of 99mTc-3PRGD2 will be intravenously injected into the patients before treatment ,the second period,the sixth period( almost three months after the initial treatment)，whole-body planar and lesions SPECT/CT to assess the value of 99mTc-3PRGD2 in evaluation of cancers.
Study: NCT02457039

Intervention type: PROCEDURE
Group type: ACTIVE_COMPARATOR
Intervention: Dense cranial electroacupuncture stimulation
Description: DCEAS is a is a novel stimulation mode in which electrical stimulation is delivered on acupoints located on the forehead.~Six pairs of acupoints are used: Baihui (GV20) and Yintang (EX-HN3), left Sishencong (EX-HN1) and Toulinqi (GB15), right Sishencong (EX-HN1) and Toulinqi (GB15), bilateral Shuaigu (GB8), bilateral Taiyang (EX-HN5), and bilateral Touwei (ST8).~Disposable acupuncture needles (Hwato®, 0.30 mm in diameter and 25-40 mm in length) are inserted at a depth of 10-30 mm perpendicularly or obliquely into acupoints. Manual manipulation is then conducted to evoke needling sensation, followed by electrical stimulation (ITO ES-160, continuous waves at 2 Hz).

Intervention type: PROCEDURE
Group type: ACTIVE_COMPARATOR
Intervention: Body acupuncture
Description: Following acupoints are used: Shui-Gou (GV26), Shen-Men (HT7). He-Gu (LI4), Wai-Guan (TE5), Zhong-Wan (CV12), Guan-Yuan (CV4), Zu-San-Li (ST36), Feng-Long (ST40) and San-Yin-Jiao (SP6).~Disposable acupuncture needles (Hwato®, 0.30 mm in diameter and 25-40 mm in length) are inserted at a depth of 10-30 mm perpendicularly or obliquely into acupoints. Manual manipulation is then conducted to evoke needling sensation. No electrical stimulation is delivered.
Study: NCT00546377

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: mitoxantrone hydrochloride

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: pentostatin

Intervention type: GENETIC
Group type: EXPERIMENTAL
Intervention: fluorescence in situ hybridization

Intervention type: GENETIC
Group type: EXPERIMENTAL
Intervention: gene rearrangement analysis
Study: NCT02457039

Intervention type: PROCEDURE
Group type: SHAM_COMPARATOR
Intervention: Least acupuncture stimulation
Description: The acupoints chosen are less related to the treated syndromes based on Traditional Chinese Medicine (TCM) theory; the number of acupoints used and the intensity of electrical stimulation are also lower than the comprehensive acupuncture regimen. The following 6 acupoints will be used in LAS control: bilateral Tong-Tian (GB17), bilateral Shou San-Li (LI10) and bilateral Fu-Yang (BL59). Electrical stimulation will be only performed on bilateral Tong-Tian (GB17) and the intensities are adjusted to a level at which patients just start feeling the stimulation.

Intervention type: DRUG
Group type: ACTIVE_COMPARATOR
Intervention: Cytoxan-containing chemotherapy regimens
Description: Each subject shall receive oral administration or venous injection or both with adjuvant or neoadujuvant chemotherapy regimens, as decided by clinical oncologist.~In clinical practice, the most commonly used Cytoxan-containing regimens include but are not limit to:~AC (x4) \[Adriamycin + Cytoxan\], TC (x4) \[Taxotere + Cytoxan\], AC-P (4+4) \[Adriamycin + Cytoxan + Paclitaxel\], TAC (x6) \[Taxotere + Adriamycin + Cytoxan\], or AC-PH (4+4) \[Adriamycin + Cytoxan + Paclitaxel + Herceptin\].

Intervention type: DRUG
Group type: SHAM_COMPARATOR
Intervention: Cytoxan-containing chemotherapy regimens
Description: Each subject shall receive oral administration or venous injection or both with adjuvant or neoadujuvant chemotherapy regimens, as decided by clinical oncologist.~In clinical practice, the most commonly used Cytoxan-containing regimens include but are not limit to:~AC (x4) \[Adriamycin + Cytoxan\], TC (x4) \[Taxotere + Cytoxan\], AC-P (4+4) \[Adriamycin + Cytoxan + Paclitaxel\], TAC (x6) \[Taxotere + Adriamycin + Cytoxan\], or AC-PH (4+4) \[Adriamycin + Cytoxan + Paclitaxel + Herceptin\].
Study: NCT03006523

Intervention type: PROCEDURE
Group type: ACTIVE_COMPARATOR
Intervention: Intrauterine insemination
Description: IUI will be performed with a Wallace® insemination 2 Catheter (Cooper Surgical, Trumbull, CT, USA) depositing 0.2 or 0.5 ml of the sperm sample at the uterine fundus. All IUIs will be performed between 12 p.m. and 4 p.m. After the procedure, 10 min of bed rest will be prescribed. Inseminations will be performed every day of the week, including weekends.

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: Intrauterine insemination
Description: IUI will be performed with a Wallace® insemination 2 Catheter (Cooper Surgical, Trumbull, CT, USA) depositing 0.2 or 0.5 ml of the sperm sample at the uterine fundus. All IUIs will be performed between 12 p.m. and 4 p.m. After the procedure, 10 min of bed rest will be prescribed. Inseminations will be performed every day of the week, including weekends.
Study: NCT00126555

Intervention type: RADIATION
Group type: EXPERIMENTAL
Intervention: Radiotherapy
Description: Undergo radiation therapy treatments once a day Monday through Friday for about 7 weeks. Each treatment takes about 15 minutes.

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: Conventional surgery
Description: Undergo surgery
Study: NCT02372396

Intervention type: BEHAVIORAL
Group type: EXPERIMENTAL
Intervention: Compassion Meditation (CM)
Description: Compassion meditation is a meditative practice focused on the wish that others and the self may be free of suffering. Because this particular form of meditation has been shown to elicit positive emotion and feelings of connection with other people, it is uniquely well suited to addressing PTSD, which is characterized by strong negative affect, deficits in positive emotion and social connectedness.

Intervention type: BEHAVIORAL
Group type: ACTIVE_COMPARATOR
Intervention: Relaxation
Description: Relaxation Training is selected as the control condition because it is a good match for nonspecific aspects of the meditative practice (e.g., attention, support, contact with a mental health provider) and it is structurally similar to meditation (e.g., restful, in session and at home exercises).
Study: NCT00456638

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Depodur
Description: Depodur vs. traditional management

Intervention type: DRUG
Group type: ACTIVE_COMPARATOR
Intervention: Depodur
Description: Depodur vs. traditional management
Study: NCT04459026

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: combination
Description: instillation and infiltration of ropivacaine
Study: NCT00126555

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: laboratory biomarker analysis
Description: Correlative studies
Study: NCT04459026

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: infiltration
Description: local infiltration ropivacaine

Intervention type: PROCEDURE
Group type: ACTIVE_COMPARATOR
Intervention: instillation
Description: intraperitoneal ropivacaine instillation
Study: NCT03543826

Intervention type: COMBINATION_PRODUCT
Group type: OTHER
Intervention: Protocol for rocuronium neuromuscular block
Description: The protocol includes specified appropriate rocuronium dosing and a valid pre-reversal assessment of the adductor pollicis response guides optimal neostigmine vs. sugammadex reversal.
Study: NCT00536003

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: progesterone
Description: vaginal capsules containing 200 mg of natural progesterone, once a day, until 36 6/7 weeks of gestation or until preterm delivery (whichever occurs first).

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: placebo
Description: vaginal capsules containing placebo, once a day, until 36 6/7 weeks of gestation or until preterm delivery (whichever occurs first).
Study: NCT03424824

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: BP1.3656 low dose
Description: Tablet, once daily oral administration at the low dose

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: BP1.3656 intermediate dose
Description: Tablet, once daily oral administration at the intermediate dose

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Placebo
Description: Tablet, once daily oral administration

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: BP1.3656 high dose
Description: Tablet, once daily oral administration at the high dose
Study: NCT01716312

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Omalizumab
Description: For each subject, treatment with omalizumab will start with a loading dose of 600 mg followed by a maintenance dose of 300 mg every 4 weeks. The study drug will be administered as a subcutaneous injection. On Week 0 and Week 16 the medication or placebo will be administered to subjects via 4 subcutaneous injections; the remaining weeks 2 injections will be administered.Subjects will be given written directions on dealing with adverse reactions. They will also receive an Epi-Pen before discharge and instructions on how to use it.

Intervention type: DRUG
Group type: ACTIVE_COMPARATOR
Intervention: Omalizumab
Description: For each subject, treatment with omalizumab will start with a loading dose of 600 mg followed by a maintenance dose of 300 mg every 4 weeks. The study drug will be administered as a subcutaneous injection. On Week 0 and Week 16 the medication or placebo will be administered to subjects via 4 subcutaneous injections; the remaining weeks 2 injections will be administered.Subjects will be given written directions on dealing with adverse reactions. They will also receive an Epi-Pen before discharge and instructions on how to use it.
Study: NCT02073396

Intervention type: DIAGNOSTIC_TEST
Intervention: Blood test
Description: Patients will undergo the tests of thrombosis, before and after stabilisation of their cardiac condition. Cardiac stabilisation will be provided by clinical cardiac teams, outside and independently from the study.
Study: NCT01306773

Intervention type: DRUG
Group type: ACTIVE_COMPARATOR
Intervention: H1N1 convalescent plasma and oseltamivir
Description: Oseltamivir 75mg bid orally during ICU hospitalization + 500mL convalescent plasma containing \>= 1:160 of neutralizing antibody to Pandemic influenza A H1N1

Intervention type: DRUG
Group type: ACTIVE_COMPARATOR
Intervention: Oral Oseltamivir alone
Description: Oral Oseltamivir 75mg bid during ICU hospitalization
Study: NCT02352311

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: DKF-313
Description: Combination of dutasteride 0.5 mg and tadalafil 5 mg

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: DKF-313
Description: Combination of dutasteride 0.5 mg and tadalafil 5 mg

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: AVODART
Description: Dutasteride 0.5 mg

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: AVODART
Description: Dutasteride 0.5 mg

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: CIALIS
Description: Tadalafil 5 mg

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: CIALIS
Description: Tadalafil 5 mg
Study: NCT04509947

Intervention type: BIOLOGICAL
Group type: EXPERIMENTAL
Intervention: Ad26.COV2.S
Description: Ad26.COV2.S will be administered as IM injection at 2-dose (high and low) levels.

Intervention type: BIOLOGICAL
Group type: EXPERIMENTAL
Intervention: Ad26.COV2.S
Description: Ad26.COV2.S will be administered as IM injection at 2-dose (high and low) levels.

Intervention type: BIOLOGICAL
Group type: PLACEBO_COMPARATOR
Intervention: Placebo
Description: Placebo will be administered as IM injection.
Study: NCT00527696

Intervention type: PROCEDURE
Group type: ACTIVE_COMPARATOR
Intervention: transvaginal obturator tape

Intervention type: PROCEDURE
Group type: ACTIVE_COMPARATOR
Intervention: transvaginal obturator tape
Study: NCT03321188

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: HIPEC
Description: HIPEC with cisplatin

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Carboplatin
Description: Adjuvant IV chemotherapy

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Paclitaxel
Description: Adjuvant IV chemotherapy
Study: NCT01136733

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Lenvatinib
Description: taken orally, once a day

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Lenvatinib
Description: taken orally, once a day

Intervention type: DRUG
Group type: ACTIVE_COMPARATOR
Intervention: Everolimus
Description: taken orally, once a day

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Everolimus
Description: taken orally, once a day
Study: NCT02884921

Intervention type: DRUG
Group type: ACTIVE_COMPARATOR
Intervention: Paracetamol
Description: Paracetamol

Intervention type: DRUG
Group type: ACTIVE_COMPARATOR
Intervention: Paracetamol
Description: Paracetamol

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Placebo
Description: Placebo
Study: NCT01509599

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: Cryotherapy: Cooling gel wrap
Description: Patients will wear compression stockings (provided), elevate legs on an elevator pillow (provided) and apply the sham cyrotherapy: cooling gel wrap during the home-based intervention

Intervention type: PROCEDURE
Group type: SHAM_COMPARATOR
Intervention: Usual care
Description: Patients will wear compression stockings (provided), elevate legs on an elevator pillow (provided) and apply the sham cyrotherapy wrap (sham) during the home-based intervention
Study: NCT00546377

Intervention type: GENETIC
Group type: EXPERIMENTAL
Intervention: polymerase chain reaction

Intervention type: GENETIC
Group type: EXPERIMENTAL
Intervention: protein expression analysis

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: flow cytometry

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: biopsy
Study: NCT02074423

Intervention type: DIETARY_SUPPLEMENT
Group type: EXPERIMENTAL
Intervention: MealShape cinnamon extract
Description: Acute administration of 1 g PO (2 capsules of 500 mg)
Study: NCT04169139

Intervention type: DEVICE
Group type: ACTIVE_COMPARATOR
Intervention: MIST (minimally invasive surgical therapy)
Description: REPaiR Periodontal Therapy
Study: NCT02635711

Intervention type: BEHAVIORAL
Group type: EXPERIMENTAL
Intervention: Adapted Taekwondo training
Description: Adapted Taekwondo training for beginners

Intervention type: BEHAVIORAL
Group type: ACTIVE_COMPARATOR
Intervention: Control
Description: Daily jogging
Study: NCT03030053

Intervention type: DIETARY_SUPPLEMENT
Group type: EXPERIMENTAL
Intervention: Cocoa-Flavanol Supplements
Description: 3 capsules each containing 300mg cocoa flavanols (total daily dose of 900mg cocoa-flavanols).
Study: NCT04169139

Intervention type: DEVICE
Group type: EXPERIMENTAL
Intervention: MIST (minimally invasive surgical therapy)
Description: REPaiR Periodontal Therapy
Study: NCT02173977

Intervention type: OTHER
Group type: ACTIVE_COMPARATOR
Intervention: ARM A- Agonist/Antagonist protocol
Description: In vitro fertilization (IVF/ICSI)

Intervention type: OTHER
Group type: ACTIVE_COMPARATOR
Intervention: ARM A- Agonist/Antagonist protocol
Description: In vitro fertilization (IVF/ICSI)

Intervention type: OTHER
Group type: ACTIVE_COMPARATOR
Intervention: ARM B- Antagonist protocol
Description: In vitro fertilization (IVF/ICSI)

Intervention type: OTHER
Group type: ACTIVE_COMPARATOR
Intervention: ARM B- Antagonist protocol
Description: In vitro fertilization (IVF/ICSI)
Study: NCT03044301

Intervention type: COMBINATION_PRODUCT
Group type: OTHER
Intervention: Intramuscular ZENEO® injection
Description: Sodium Chloride (0.9 %)

Intervention type: COMBINATION_PRODUCT
Group type: OTHER
Intervention: Intramuscular ZENEO® injection
Description: Sodium Chloride (0.9 %)

Intervention type: COMBINATION_PRODUCT
Group type: OTHER
Intervention: Intramuscular ZENEO® injection
Description: Sodium Chloride (0.9 %)

Intervention type: COMBINATION_PRODUCT
Group type: OTHER
Intervention: Subcutaneous high ZENEO® injection
Description: Sodium Chloride (0.9 %)

Intervention type: COMBINATION_PRODUCT
Group type: OTHER
Intervention: Subcutaneous low ZENEO® injection
Description: Sodium Chloride (0.9 %)
Study: NCT04303897

Intervention type: DEVICE
Intervention: XEN Glaucoma Stent
Description: Data are collected from patients who are implanted with XEN via the specific urgent medical needs for named patient use regulatory pathway in Hainan
Study: NCT04227782

Intervention type: DIAGNOSTIC_TEST
Intervention: Magnetic Resonance Imaging
Description: Magnetic Resonance Imaging

Intervention type: DIAGNOSTIC_TEST
Intervention: Magnetic Resonance Imaging
Description: Magnetic Resonance Imaging

Intervention type: DIAGNOSTIC_TEST
Intervention: Magnetic Resonance Imaging
Description: Magnetic Resonance Imaging

Intervention type: DIAGNOSTIC_TEST
Intervention: Magnetic Resonance Imaging
Description: Magnetic Resonance Imaging

Intervention type: OTHER
Intervention: Stable Isotope Study
Description: Stable Isotope study

Intervention type: OTHER
Intervention: Stable Isotope Study
Description: Stable Isotope study

Intervention type: OTHER
Intervention: Stable Isotope Study
Description: Stable Isotope study